laboratory of advanced materials for special applications

Transcription

National Institute of Materials Physics
----------------------------------------------------------------------------------------------------(Institutul Naţional de Cercetare-Dezvoltare pentru Fizica Materialelor)
DIRECTORATE
Director: Dr. Lucian Pintilie
Scientific Director: Dr. Florin Vasiliu
ADDRESS
P.O. BOX MG – 7
Bucharest – Magurele / ROMANIA
Tel. (+4) 021 369 01 85
Fax (+4) 021 369 01 77
E-Mail
L. Pintilie: [email protected]
F. Vasiliu: [email protected]
WWW
http: // www.infim.ro
Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
Laboratories and Researchers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Awards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selected Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
29
31
Fundamentals of Condensed Matter Physics at Meso and Nanoscale. . . . .
31
Nano-objects, Thin Films and Multifunctional Materials . . . . . . . . . . . . . .
Publications and Presentations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
55
85
Books . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
86
Journals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
87
Conference proceedings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
104
Contributed presentations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
108
Invited lectures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Seminaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
122
125
Patents and patent requests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
127
International Cooperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
129
International cooperation projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
130
Bilateral cooperation projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
133
2
PREFACE
The National Institute of Materials Physics (NIMP-Bucharest, Romania) is devoted to fundamental
and applied research and development, with particular emphasis in the fields of solid state physics
and materials research.The institute management has tried deliberately to develop a balanced policy
of basic and application-oriented research. NIMP finances the major part of its activities through
Core Funding Program and through National R&D Programs (PARTNERSHIPS, IDEAS,
CAPACITIES, PEOPLE, etc), promoted by the Romanian Ministry for Education, Research,
Youth and Sport (MECTS). The institute has presently about 234 workers, of which 186 are
directly involved in research activities. NIMP has 150 researchers, and among them are 15 PhD
supervisors, 89 doctors, 40 PhD students, and 10 Master students.
The year 2009 was very difficult, due to the global economic crisis. The public budget for research
was reduced with about 60 %, compared to 2008, from about 0.5 % GDP to about 0.19 % GDP.
This had led to a reduction of incomes for NIMP, from about 53 million lei in 2008 to about 33
million lei in 2009. However, the NIMP strategy was to further develop its research infrastructure
and to further attract young graduate students for the research carrier. Some new equipments were
purchased in 2009, especially through the POS-CCE project, but also through the Core Program.
Among these we can mention: a cryoprober station with vertical magnetic field from LakeShore; a
ferroelectric tester for thin films and heterostructures from AixACCT; a DLTS system, the only one
from the country; a fluorescence microscope; an ultra-performant Raman Microscope; a SARPES
system which has been attached to the MBE cluster for surfaces and interfaces physics.
3
In 2009 all the 6 Capacities projects were completed successfully. This fact led also to new
infrastructure in the institute, namely: a digital RES platform; a complex RF magnetron sputtering
equipment, with in-situ characterization facilities (Auger spectroscopy, LEEM, ellipsometry); a low
temperature Mossbauer spectrometer; a laboratory for preparation and characterization of polymer
and biological thin films; high resolution XPS and STM for surface analysis; a complete laboratory
for ceramic samples preparation by non-conventional methods (spark plasma sintering, hot pressing,
microwave sintering, thermal constants analyser).
The budgetary constraints and the financial insecurity have affected the NIMP scientific output,
mainly because of the stress produced by the large delays in cash flow, including funds for salaries.
Despite the unfavorable conditions, NIMP still have published 125 papers in ISI journals with
impact factor, 27 papers in journals which still do not have an impact factor but are cited on Web
of Science, and 9 papers in other journals. There were also 8 patents and patent requests and 60
contributions to national and international conferences.
Researchers from NIMP have won several prizes in 2009, among which: 3 Romanian Academy
prizes; a gold medal to PROINVENT exhibition in Cluj-Napoca; the first place for research
institutions in Ilfov county.
Because in 2009 there was no competition for new projects, there are no changes in the list of
funded projects to Ideas and Partnership programs. However, the funding for all projects was
severely cut, and some projects which were won to the 2008 competition are still not funded (no
contract was signed because of lack of funds, as for example for the projects won in the frame of
program "Complex Project of Exploratory Research").
At international level, NIMP is partner in a newly won FP7 project, large collaborative type, called
Interfaces in Oxides (IFOX). Also is member in a FP7 Marie Curie training network on Particle
Detectors (MC-PAD). NIMP is also member in a FP6 Network of Excellence (MAGMANET),
and one of our colleagues (Adrian Crisan) had won a Marie Curie Excellence grant at University of
Birmingham. Other on-going international projects with NIMP participation are: the RD-50
project of CERN; 4 COST actions; 2 HASYLAB projects; 4 Erasmus and Brancusi projects; 4
bilateral agreements funded by module III-Capacities; about 40 collaborations with research
institutions from abroad.
Unfortunately the funding for 2010 will be at the same level as in 2009. No major achievements in
the infrastructure will be possible, except those already envisaged in the frame of POS-CCE project,
which will end in February 2011.
We hope, however, that contrary to the problems generated by the reduced funding, we will manage
to maintain the leading place of NIMP in the Romanian research system. It is very interesting to
mention that in a recent report made public by Scopus (“SCImago Institutions Rankings 2009
World Report”), NIMP is among the only three National Institutes ranked from Romania (see the
following table)
4
Rank Organization
Country
Sector
879 Universitatea Politehnica
din Bucuresti
1034 Universitatea din
Bucuresti
1485 Universitatea Babes-Bolyai
din Cluj-Napoca
1492 National Institute for
Laser, Plasma
and Radiation Physics
1585 National Institute of
Materials Physics
1655 Horia Hulubei National
Institute of Physics and
Nuclear Engineering
1916 Universitatea din Craiova
Romania
2396
1904
3.32 50.37
0.99
0.74
950
2.38 49.37
0.95
0.75
Romania
Higher
educ.
Higher
educ.
Higher
educ.
Government
Int. Norm. Norm.
Coll.
SJR
Cit.
0.98 31.80
0.88 0.37
943
3.17 67.76
0.99
0.80
Romania
Government
809
2.66 64.03
1.01
0.72
Romania
Government
736
3.73 78.40
0.99
0.74
Romania
Higher
educ.
Higher
educ.
507
1.32 29.39
0.85
0.48
379
0.95 38.52
0.64
0.58
Romania
Romania
2067 Universitatea Tehnica din Romania
Cluj-Napoca
Output
CxD
This report shows that the research from NIMP is of very good quality, and that our researchers
benefit of international recognition. We hope that such reports will help the Romanian
Government to change its policy towards research, distributing the funds to the institutions which
are really visible at international level.
Dr. Lucian Pintilie
General Director
Bucharest, March 20109
5
6
Personnel
Laboratories
and Researchers
7
Laboratories and Researchers
Personnel
Laboratory of Advanced Materials for Special Applications
HEAD:
Dr. Mihail Florin LAZARESCU
E-mail: [email protected]
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
A. Group of Single-Crystal Growth and Materials Characterization
HEAD:
1.
2.
3.
4.
5.
6.
7.
8.
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
Dr. Adrian Stefan MANEA
Dr. Constantin LOGOFATU
Dr. Rodica GHITA
Constantin NEGRILA
Constantin COTARLAN
Florica UNGUREANU
Doina RADULESCU
senior researcher I
senior researcher II
senior researcher III
researcher
assistant researcher
engineer
XPS, AES, UPS, STM (SPECS) characterization system
8
Personnel
B. Group of Physics of High Frequency Materials and Devices
HEAD:
1.
2.
3.
4.
5.
6.
7.
8.
1
Dr. Andrei IOACHIM
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
Dr. Andrei IOACHIM
Dr. Marian Gabriel BANCIU
Dr. Mariana Irina TOACSĂN
Liviu NEDELCU
Dragos GHETU
Constantin Augustin DUŢU1
Marian IOSIF
Alexandru GAVRILA
senior researcher
researcher
research assistant
research assistant
engineer
engineer
Université Catholique de Louvain, Belgium
9
Personnel
Laboratory of Low Temperature Physics and Superconductivity
HEAD:
Dr. Lucica MIU
Tel.: (+4) 021 36901 85
Fax: (+4) 021 369 01 77
1. Dr. Lucica MIU
2. Dr. Gheorghe Virgil ALDICA
3. Dr. Adrian Ioan CRISAN 1
4. Dr. Stelian POPA
5. Dr. Viorel Constantin SANDU
6. Dr. Mihai VELTER-STEFANESCU
7. Dr. Petre BADICA
8. Dr. Valentina MIHALACHE
9. Monica Maria POPA
10. Ion IVAN
1
senior researcher I
senior researcher I
senior researcher I
senior researcher I
senior researcher I
senior researcher I
senior researcher I
researcher
Univ Birmingham, Dept Met & Mat, Birmingham, England
10
Personnel
Laboratory of Physics of Semiconductor Materials
and Complex Structures
HEAD:
1.
2.
3.
4.
5.
6.
1
2
Dr. Ioana PINTILIE
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
Dr. Ioana PINTILIE
Dr. Lucian PINTILIE
Viorica STANCU
Marian LISCA1
Andreia POPA2
M. Sc. Cristina DRAGOI
senior researcher I
senior researcher I
junior researcher
Friedrich-Schiller University, Jena, Germany
International Max Planck Research School, Dresden, Germany
Set-up for electrical measurements at low temperatures
11
Personnel
Laboratory of Solid State Magnetism
HEAD:
Dr. Mihaela VALEANU
Tel : (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
A. Group of Electronic Processes via Nuclear Gamma Resonance
HEAD:
1.
2.
3.
4.
5.
6.
Dr. Victor KUNCSER
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
Dr. George FILOTI
Dr. Victor KUNCSER
Dr. Ovidiu CRISAN
Dr. Daniela PREDOI
Dr. Petru PALADE
Gabriel SCHINTEIE
senior researcher I
senior researcher I
researcher
Mossbauer spectrometer with cryogenic free close cycle cryostat
12
Personnel
B. Group of Magnetism and Magnetic Materials
HEAD:
Dr. Mihaela VALEANU
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
1. Dr. Mihaela VALEANU
2. Dr. Dorin Petru LAZAR
3. Dr. Andrei GALATANU
4. Dr. Adrian JIANU 1
5. Dr. Stanica ENACHE
6. Dr. Marilena TOMUT 2
7. Felicia TOLEA
8. Alina CRISAN
9. Dr. Catalin Aurelian GALCA
10. Dr. Carmen PLAPCIANU
11. Cristina VALSANGIACOM
12. Bogdan POPESCU
13. Mihaela SOFRONIE
14. Ancuta BARSAN
senior researcher I
senior researcher I
senior researcher I
senior researcher I
researcher
researcher
researcher
researcher
researcher
Institute for Pulsed Power and Microwave Technology,
Forschungszentrum Karlsruhe
2
GSI / KP2 Nuclear Structure and Nuclear Chemistry Darmstadt
1
Laser flash thermal constants analyser
Equipment for microwave sintering
Equipment for hot press sintering
13
Personnel
Laboratory of Low-Dimensional Systems
HEAD:
Dr. Magdalena Lidia CIUREA
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
A. Group of Theoretical Physics: Condensed Matter
HEAD:
1.
2.
3.
4.
5.
6.
7.
1
2
Dr. Alexandru ALDEA
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
Dr. Alexandru ALDEA
Dr. Andrei MANOLESCU 1
Dr. Paul GARTNER 2
Dr. Marian NITA
Dr. Valeriu MOLDOVEANU
Ion-Viorel DINU
Mugurel TOLEA
senior researcher I
senior researcher I
senior researcher I
researcher
researcher
Univ Iceland, Institut of Science, Reykjavik, Iceland
Univ Bremen, Inst Theoret Phys, D-28334 Bremen, Germany
14
Personnel
B. Group of Structure and Thin Films
HEAD:
1.
2.
3.
4.
5.
6.
7.
8.
Dr. Dan MACOVEI
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
Dr. Dan MACOVEI
Dr. Nicolae POPA
Dr. Cristian-Mihail TEODORESCU
Dr. Iuliana PASUK
Marius Adrian HUSANU
George Adrian LUNGU
Nicoleta Georgiana GHEORGHE
Adi SEGAL
senior researcher I
senior researcher I
senior researcher I
researcher
student
Molecular Beam Epitaxy (MBE) deposition system
15
Personnel
C. Group of Thin Films and Quantum Structures
HEAD:
1.
2.
3.
4.
5.
6.
7.
1
2
Dr. Toma STOICA
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
Dr. Toma STOICA 1
Dr. Constantin MOROSANU
Dr. Tionica STOICA
Dr. Paul Nicolae RACEC 2
George STAN
Adrian SLAV
Dan Antoniu MARCOV
senior researcher I
researcher, PhD candidate
assistant researcher, PhD candidate
assistant researcher, PhD candidate
KFA Julich GmbH, Forschungszentrum, Inst Bio & Nanosyst, Julich, Germany
Tech Univ Cottbus, Cottbus, Germany
16
Personnel
D. Group of Silicon-Based Micro- and Nanosystems
HEAD: Dr. Magdalena Lidia CIUREA
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
1.
2.
3.
4.
5.
6.
7.
1
Dr. Magdalena Lidia CIUREA
Dr. Sorina LAZANU,
Dr. Gheorghe IORDACHE
Dr. Mihai DRAGHICI1
Ionel STAVARACHE
Elena RUSNAC
Ana Maria LEPADATU
senior researcher I
senior researcher I
researcher
researcher
University of Roskilde, Denmark
Magnetron sputtering equipment
17
Personnel
E. Group of Gas Sensors
HEAD:
Dr. Adelina TOMESCU
Tel: (+4) 021 369.01.85
Fax: (+4) 021 369.01.77
1. Dr. Adelina TOMESCU
2. Dr. Nicolae BARSAN 1
3. Dr. Alexandru OPREA 1
4. M. Sc. Razvan Mihai ROESCU 2
5. Irina DUMITRIU
6. Cristian Eugen SIMION
1
2
senior researcher I
Inst. fuer Physikalische Chemie, Tubingen University, Germany
Angewandte Festkörperphysik, Ruhr-Universität Bochum, Germany
18
Personnel
F. Group of X-Ray Diffraction,
Modelling and Langmuir-Blodgett Films
HEAD: Dr. Mihai POPESCU
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
1.
2.
3.
4.
5.
Dr. Mihai POPESCU
Dr. Adam LORINCZI
Florinel SAVA
Alin VELEA
Daniel-Iosif SIMANDAN
senior researcher I
senior researcher
19
Personnel
Laboratory of Optics and Spectroscopy
HEAD:
Dr. Mihaela BAIBARAC
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
A. Group of Optics
HEAD: Dr. Ioan BALTOG
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
1. Dr. Ioan BALTOG
2. Dr. Mihaela BAIBARAC
3. Lucian MIHUT
4. Timucin VELULA
5. Malvina SCOCIOREANU
6. Ioana DUMITRESCU
7. Ion SMARANDA
8. Ilarie GONTIA
senior researcher I
senior researcher I
Raman spectrophotometer
20
Personnel
B. Group of Liquid Crystals and Surface Interaction
HEAD:
1.
2.
3.
4.
5.
Dr. Stefan FRUNZA
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
Dr. Stefan FRUNZA
Dr. Ligia FRUNZA
Traian BEICA
Irina Ionela ZGURA
Paul Constantin GANEA
senior researcher I
senior researcher I
researcher
Drop Shape Analysis System
21
Personnel
C. Group of Nanostructurated Materials
HEAD: Dr. Marian SIMA
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
1.
2.
3.
4.
Dr. Marian SIMA
Dr. Mihai SECU
Dr. Corina SECU
Mariana SIMA
senior researcher I
researcher III
Set-up for thermoluminescence measurements
22
Personnel
D. Group of Organic Crystals, Ionic Conductivity and Electrodiffusion
HEAD: Dr. ANCA STANCULESCU
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
1.
2.
3.
4.
5.
6.
Dr. Anca STANCULESCU
Dr. Ionut ENCULESCU
Dr. Nicoleta PREDA
Marcela SOCOL
Elena MATEI
Oana GRIGORESCU
senior researcher I
researcher
researcher
Near field microspectrometer with low
temperature capabilities
Scanning near field optical microscope with
AFM facilities
23
Personnel
E. Group of Point Defects Spectroscopy in Optical Materials
HEAD: Dr. SILVIU POLOSAN
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
1. Dr. Silviu POLOSAN
2. Dr. Elena APOSTOL
3. Dr. Monica ENCULESCU
24
Personnel
Laboratory of Oxidic Materials
HEAD:
1.
2.
3.
4.
5.
6.
7.
8.
9.
1
Dr. Cornel MICLEA
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
Dr. Cornel MICLEA
Dr. Constantin TANASOIU
Dr. Luminita AMARANDE
Dr. Igor NAZARENCO
Dr. Alin IUGA
Dr. Corneliu Florin MICLEA 1
Lucian TRUPINA
Marius CIOANGHER
Vasilica TOMA
senior researcher I
senior researcher I
researcher
researcher
Max Planck Institute for Solid State Physics, Dresden, Germany.
25
Personnel
Laboratory of Structure and Dynamics of Condensed Matter
HEAD:
Dr. Lucian DIAMANDESCU
Tel: (+4) 021 369.01.85
Fax: (+4) 021 369.01.77
A. Physics of Transient Phenomena and Mössbauer Spectroscopy Group
HEAD:
1.
2.
3.
4.
5.
6.
Tel: (+4) 021 369.01.85
Fax: (+4) 021 369.01.77
Dr. Ion BIBICU
Dr. Serban CONSTANTINESCU
Dr. Doina TARABASANU-MIHAILA
Dr. Marcel FEDER
Dr. Alina BANUTA
senior researcher I
senior researcher I
senior researcher I
senior researcher I
Mössbauer spectrometer
26
Personnel
B. Group of Electron Microscopy, X-Ray and Neutron Diffraction
HEAD: Dr. Florin VASILIU
Tel.: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
1.
2.
3.
4.
5.
6.
Dr. Florin VASILIU
Dr. Nicoleta POPESCU-POGRION
Dr. Corneliu SARBU
Dr. Mihai VLAICU
Dr. Manuela STIR 1
Ionel MERCIONIU
1
senior researcher I
senior researcher I
senior researcher I
Empa Materials Science & Technology, CH-3602, Thun, Switzerland
27
Personnel
Laboratory of Microstructure of Defects in Solid Materials
HEAD:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Dr. Sergiu V. NISTOR
Tel: (+4) 021 369 01 85
Fax: (+4) 021 369 01 77
Dr. Sergiu V. NISTOR
Dr. Valentin S. TEODORESCU
Dr. Leona C. NISTOR
Dr. Nicoleta M. GRECU
Dr. Corneliu GHICA
Dr. Mariana STEFAN
Dr. Carmencita D. MATEESCU
Dr. Daniela GHICA
Adeluta TARPAN
Adrian MARALOIU
Brandusa MIRONOV
senior researcher I
senior researcher I
senior researcher I
senior researcher I
senior researcher I
Digital platform for advanced RES techniques including microwave bridge in Q band
28
Personnel
Awards
Awards
1. Beica T., Frunza S., Zgura I., Moldovan R., Dinescu A.
Diploma of Excellence and Gold Medal PROINVENT 2009 - International Salon of Research,
Innovation and Inventics, 7th Edition, Cluj-Napoca, 24 – 27 march 2009 for the invention
“Method, measurement cell and experimental set-up for the estimation of the temperature
dependence of the liquid crystal optical birefringence”
Patent no 122061B1
2. Enculescu M.
DRAGOMIR HURMUZESCU Prize of the Romanian Academy for year 2007, Physics
Section, for the subject “Study of nanostructures obtained by template method”
3. Ghica C.
CONSTANTIN MICULESCU Prize of the Romanian Academy for year 2007, Physics Section,
for the subject “Extended structural defects in advanced materials”
4. Miclea C., Tanasoiu C, Cioangher M.
Diploma of Excellence and Gold Medal PROINVENT 2009- International Salon of Research,
Innovation and Inventics, 7 th Edition, Cluj Napoca, 24 – 27 march 2009 for the invention
“Piezoceramic ultrasonic transducer for avoiding of deposited layers on the internal walls of heat
exchangers”
5. Negrila C., Iuga A., Ghita R., Logofatu C., Cernea M., Manea S., Lazarescu M.
Diploma of Excellence and Gold Medal PROINVENT 2009 - International Salon of Research,
Innovation and Inventics, 7th Edition, Cluj-Napoca, 24 – 27 march 2009 for the inventions
“Assembly and method for control; of growth processes of semiconducting crystals”
Patent no. 122367 B1
and
“Patterning procedure for Schottky structures on Ga As substrates”
Patent no. 122793 B1
6. Pintilie L.
CONSTANTIN MICULESCU Prize of the Romanian Academy for year 2007, Physics Section,
for the subject “Study of some epitaxial ferroelectric layers”
29
30
Selected Results
Fundamentals of Condensed Matter
Physics at Meso and Nanoscale
31
Fundamentals of Condensed Matter Physics at Meso and Nanoscale
Selected Results
Anti-Stokes Raman scattering as an efficient tool for revealing functionalized
carbon nanotubes
M. Baibarac, I.Baltog
in cooperation with
S.Lefrant
Institut des Materiaux “Jean Rouxel”, 2 rue de la Houssinière, B.P. 32229,
F-44322, Nantes, France
The capability of anti-Stokes/Stokes Raman
spectroscopy to evaluate chemical interactions at
the interface of conducting polymer/carbon
nanotubes is demonstrated. Focusing on poly
(3,4-ethylenedioxy thiophene) (PEDOT)/single
walled carbon nanotubes (SWNT) composites,
comparative Raman studies in the Stokes and
anti-Stokes branches provide new information
about the doped and un-doped states of the
polymer which are difficult to be obtained by
conventional Raman measurements. Some
particular properties of anti-Stokes emission,
which usually characterize a coherent anti-Stokes
Raman scattering (CARS) type process are
revealed when a resonant optical excitation is
used. Normally, in such a case named as
resonant Raman scattering (RRS), the Raman
spectrum reveals a certain sensitivity and
selectivity, only the vibrations coupled to the
chromophoric groups responsible for the
absorption bands are intensified both in Stokes
and anti-Stokes branches. Things become more
complicated when the investigated material is
deposited as thin film on a metallic support (Au,
Ag), in which by the surface plasmons excitation,
a surface enhancement Raman scattering (SERS)
process operates. In this context, two important
experimental facts, not theoretically elucidated,
was observed in the anti-Stokes branch: i) an
abnormal enhancement of the Raman lines
intensity that increases gradually with the of the
Raman shifts [1]; ii) a quadratic dependence of
the SERS intensity on the incident laser power
was found [2].
Another point of view is to
consider the abnormal anti-Stokes emission as a
new optical phenomenon. The Raman effect is
one example of a complex interaction between
the incident electromagnetic wave (EM) and the
32
material’s molecular/atomic structure. Under the
oscillating EM field of the exciting light, a
periodic separation of charge results in the
electron cloud which is called an induced
molecular dipole moment, P. The oscillating
induced dipole moment manifests itself as a
source of secondary EM radiation, thereby
resulting in scattered light. The strength of the
induced dipole moment, P, is given by P = αE,
where α is the polarizability and E = E0(cos2ω0t
+ ϕ0) is the strength of electric field of the
incident EM wave. On the macroscopic scale,
the material response to resonant EM excitation
is described by polarization P = P0 + χ(1) E + χ(2)
EE + χ(3) EEE +.. A priori, the appearance in the
P expression of higher order terms as χ(2) EE and
χ(3) EEE is equivalent to fulfilling the key
condition to generate a nonlinear optical
process. In this context we look the abnormal
anti-Stokes Raman emission, as a new
phenomenon reminiscent to a nonlinear optical
process. Own investigation revealed new
dependences for the anti-Stokes emission: i) the
intensity of anti-Stokes Raman lines increases
with the vibrational wavenumber; ii) a square
dependence on the film thickness; iii) a square
dependence on the exciting laser intensity; iv) a
linear dependence on the numerical aperture
(NA) of the microscope objective used for the
detection of the anti-Stokes emission ; v) the
polarization ratio on the anti-Stokes side is
always greater in comparison with that measured
for a spontaneous Stokes Raman emission [3-5].
All these features cannot be explained by existing
theories associated both with the resonant
Raman effect and SERS mechanism and
surprisingly, they are also encountered in the
CARS type emission.
600
b1 ρ1590 cm = 116
-1
-1500 -1200 -900 -600
600
1571
900 1200 1500
Fig.1 Stokes and anti-Stokes Raman spectra at λexc
= 514.5 nm of PEDOT electrodepo-sited by cyclic
voltammetry on a Au rough plate with stopping
at: a) -1 V vs. Ag/Ag+ (9 CV) that lead to undoped form and b) +1.6 V vs. Ag/Ag+ (9CV) that
lead to doped form. The red (dashed) curves show
the anti-Stokes replica calculated with the
Maxwell-Boltzmann formula applied to the Stokes
spectra.
80
60
40
20
0
0 300 600 900 12001500
Wavenumber (cm-1)
Fig.2 PEDOT in doped form. Anti-Stokes Raman
intensity, (Iexp/Icalc)aS , as a function of the
wavenumber. λexc = 676.4 nm
0
-240 -180 -120
b2 -176
2400
1800
1200
1310
436
574
1438
λexc = 676.4 nm
852
989
600
600
300 600 900 1200 1500
0
3000
b3
2000
0
-1650 -1500 -1350
Wavenumber / cm-1
(Iexp/Icalc)aS
-1591
150
0
a3
4000
2000
1000
0
-240 -180 -120
λexc = 676.4 nm
1544
0
-1650 -1500 -1350
6000
990
442
576
1366
-576
-990
-1450
0
-1426
150
300
200
2400
1200
-1321
300
450
-175
1307
-1500 -1200 -900 -600
600 900 1200 1500
PEDOT deposited on Au by cyclic voltammety at +1.6 V (9 CV)
12000
400
b
1450
ρ= 1
-442
a2
1800
-1426
1513
1366
990
440
572
-572
-990
-1513
-1366
Raman Intensity / Arbitr.Units
6000
0
0
450
12000
-1593
1432
-1432
Raman Intensity / Arbitr.Units
-440
ρ = 13.8
400
200
a1 ρ
= 163
1585 cm
-1
a
175
600
PEDOT deposited on Au by cyclic voltammety at -1 V (9 CV)
1562
176
Selected Results
300 600 900 1200 1500
0
Wavenumber / cm-1
Fig.3 Stokes and anti-Stokes Raman spectra at λexc
= 676.4 nm of PEDOT in doped form on
SWNTs film layered on an Au plate (a1;a2;a3). In
(b1;b2;b3) are shown the Raman spectra after an
interaction with 1M NH4OH solution. The red
(dashed) curves show the anti-Stokes replica
calculated with the Maxwell-Boltzmann formula
applied to the Stokes spectra.
Main results are: i) abnormal and anti-Stokes
Raman emission appears under resonant optical
excitation of PEDOT, (Fig.1); ii) as in a CARS
type process, the intensity of anti-Stokes
Raman lines increases gradually with the of the
Raman shifts, (Fig.2); iii) un-doped and
doped PEDOT forms are characterized by
different Raman scattering efficiencies. For
PEDOT/SWNTs only the Raman lines
associatyed with the un-doped PEDOT form
are visible in the anti-Stokes Raman branch,
(Fig.3).
References
[1] T.L. Haslett, L. Tay, M. Moskovits,
J.Chem.Phys. 113, 1641, (2000)
[2] K. Kneipp, Y. Wang, H. Kneipp, I. Itzkan,
R.R. Dasari, M.S. Feld, Phys. Rev. Lett. 76
2444, (1996)
[3] I.Baltog, M. Baibarac, S. Lefrant, Phys Rev B;
72, 245402, (2005)
[4] I. Baltog, M. Baibarac, S. Lefrant, J. Phys:
Condensed Matter. 20, 275215, (2008)
[5] M. Baibarac, I. Baltog, S. Lefrant, Carbon,
47, 1389, (2009)
33
Selected Results
New Fe3Ln tetra-nuclear complexes with remarkable magnetic properties
G. Filoti, V. Kuncser, G. Schinteie
in cooperation with
J. Bartolomé
Instituto de Ciencia de Materiales de Aragón and Departamento de Física Materia Condensada, CSIC–
Universidad de Zaragoza, 50009 Zaragoza, Spain
V. Mereacre, D. Prodius, C. Turta
Laboratory of Bioinorganic Chemistry, Institute of Chemistry of the Academy of Sciences of Moldova,
Chisinau, Moldova
C. E. Anson, A. K. Powell
Institute of Inorganic Chemistry, University of Karlsruhe, Karlsruhe, Germany
New
tetra-nuclear
complexes
[Fe3Ln(µ3O)2(CCl3COO)8(H2O)(THF)3]∙THF (Ln = CeIII
(1), PrIII (2), NdIII (3)) and
[Fe3Ln(µ3O)2(CCl3COO)8(H2O)(THF)3]∙THF∙C7H16 (Ln =
SmIII (4), EuIII (5), GdIII (6), TbIII (7), DyIII (8),
HoIII (9), LuIII (10) and YIII (11)) have been
successfully [1] synthesized. These isostructural
molecules have a non-planar {Fe3Ln(µ3-O)2}
“butterfly” core as evidenced by Fig. 1.
The χT product (Fig 2) values at room temperature for the Y and Lu compounds suggest an
asymmetric Fe3 unit with strong (J/kB ≈ -50 K)
anti-ferromagnetic coupling between each of the
Few wing-located, Fe(1) or Fe(3), and the body Feb
central Fe(2) one. The Fe3 unit has a robust S = 5/2
ground state, with two spins parallel (Fe(1) and
Fe(3)) and one anti-parallel (Fe(2). The
compounds 6-9 show much higher values of χT at
300 K, pronouncedly decreasing below ca. 50 K.
This effect was related to the anti-ferromagnetic
coupling between the Fe3 tri-nuclear unit and the
magnetic LnIII cations. As may be expected, the
complexes containing diamagnetic (LuIII 10, YIII
11) or isotropic (GdIII 6) lanthanides show clear
saturation above ca. 60 kOe. The saturation values
for 10 and 11 (Fig.3a) are ca. 4.7 µB, in agreement
with the expected value for three strongly antiferromagnetically coupled FeIII centers with an
overall S = 5/2 ground state, as above mentioned.
The magnetization (Fig.3b) for 6 saturates at ca.
11.8 µB at 90 kOe, close to the sum of the values
for S = 7/2 GdIII and an S = 5/2 Fe3 unit. For the
complexes containing anisotropic lanthanide
cations, there is a clear distinction between the
34
lighter and heavier lanthanides. Compounds 1 – 5
(4f1 to 4f6) show either near or complete saturation
behavior. By contrast, compounds 7 - 9 (4f8 – 4f10)
show no saturation of their magnetization as
expected in presence of low lying excited states and
magnetic anisotropy. The high spin S =5/2 of
Fe(III) atoms was ratified, via the IS and Bint,
provided by Mössbauer investigation, which also
detailed the specific interaction on the two
different Few and Feb locations in the molecule. At
3 K a spin blocking was demonstrated (for the first
time) to occur in tetra- nuclear complexes Fe3TbO2
and Fe3DyO2 (Fig. 4a) in the Mössbauer time
window, via the presence of the sextet patterns
without any external applied fields, in agreement
with the SMM behavior evidenced by the ac
susceptibility measurements. The Mössbauer “in
field” data proved unambiguously the anti-parallel
spin orientation of the Feb and Few. Comparing “in
field” behavior (Fig.4b), the Beff’s (absolute
novelty), in Fe3LuO2, Fe3TbO2 and Fe3DyO2,
increase for Feb and decrease for Few, while in
Fe3GdO2, the trend is the opposite, due to
isotropic character of the Gd ion, which is
polarized in the direction of the applied field for
Bappl ≈ 60 kOe.
The lack of anisotropy is also confirmed by the
absence of spin blocking at lowest measuring
temperature. The spectra of Fe3DyO2 and Fe3YO2
acquired in a temperature range 80 – 295 K put in
evidence that both the quadrupole interaction, QS
and isomer shift, IS are influenced by the specific
electron transferability of each of the specific four
types of oxygen ions Ooxo, Ocarb, OTHF and OH2O,
Selected Results
existing in the molecule, the inter ionic distances
and their coupling bonds playing the crucial role.
In this way could be explained (original evaluation
approach) the evidently smaller IS for Feb and its
QS peculiar temperature behavior.
Fig.3a Field dependence (at 1.8 K) of the
magnetization for compounds 1–5, 10, 11
500
400
Beff(kOe)
Fig.1. [Fe3HoO2(CCl3COO)8(H2O)(THF)3]
·THF·C7H16 complex structure
Fig.3b Field dependence of the magnetization for
compounds 6 – 9 at 1.8 K.
300
200
100
a
Bw
Bw
Bb
Fe3Lu
0
0 10 20 30 40 50 60 70
500
Beff(kOe)
400
300
200
100
b
Fe3Gd
c
Fe3Tb
Beff(kOe)
0
0 10 20 30 40 50 60 70
500
450
400
350
0 10 20 30 40 50 60 70
500
Beff(kOe)
450
400
d
Fe3Dy
350
0 10 20 30 40 50 60 70
Bappl(kOe)
Fig.2. Temperature dependence of the χT product
for 1 – 5, 10, 11 (upper) and 6 - 9 (lower).
Fig.4 Fe3DyO2 Mossbauer spectra at 3 K at
various applied fields.(left). Effective fields (Beff)
dependence on applied fields (Bappl) for a){Fe3LuO2},
b){Fe3GdO2}, c){Fe3TbO2}, d){Fe3DyO2}; Few (●,■)
and Feb () (right).
References
1. V. Mereacre, D. Prodius, C. Turta, S. Shova,
G. Filoti, J. Bartolomé, R. Clérac, C.E. Anson,
A. K. Powell, Polyhedron 28, 3017-28(2009)
2. J. Bartolomé, G. Filoti, V. Kuncser, G. Schinteie,
V. Mereacre, C.Anson, A. Powell,, D. Prodius, C.
Turta, Phys. Rev. B 80, 014430 (2009)
35
Selected Results
Insights into cyanobiphenyl liquid crystals: some bulk properties and specific
interactions with the substrate in confinement
S. Frunza, L. Frunza, T. Beica, I. Zgura,
in cooperation with
R. Moldovan
Romanian Academy Center of Advanced Studies in Physics, Bucharest, Romania
D. Stoenescu
Nemoptic, 1 rue Guynemer, F-78114 Magny-les-Hameaux, France
and
H. Kosslick
Leibniz Institute for Catalysis at the University of Rostock, D-18059 Rostock, Germany
36
1.07
0.006
4
4CB
5CB
6CB
7CB
8CB
3
0.004
∆ρ, g/cm3
Relative variation of volume ⋅10
3
variation of that part of the density which
depends on the order parameter: the
importance of the degree of ordering in the
liquid crystal for the density is clearly revealed.
In addition, there is a deviation from the linear
behaviour of the temperature dependence of
density (not shown here) which obeys the rule
of the corresponding states of Simoes and
Simeao.
2
1
0
4
5
6
7
0.002
8
0
Carbon atoms in the alkyl chain
-20
-10
0
10
20
T-TNI , K
Density, g/cm3
The liquid crystal 4-cyano-4’-pentylbiphenyl
was discovered in 1973 by Gray: at the time it
was the first member of what is now wellknown and extensively studied 4’-alkyl
cyanobiphenyl homologous series (nCB, n is the
number of carbon atoms in the alkyl tail). The
series members have the liquid crystalline phase
transitions near room temperature, which can
be an advantage for their use in displays.
The interest in accurate determination of
the density of a liquid crystal around the
transition temperatures comes from the
experimental evidence about the order of phase
transition. The CBs investigated [1] spread
from the 3rd to the 8th homologues. Careful
automatic measurements were performed [1]
with Anton Paar densimeter (model DMA
4500) in the nematic and isotropic phases with
the precision of ±1·10-5g/cm3. A program was
written to ensure the validation of the results
given by the instrument and to allow reaching
the thermal equilibrium.
The results (Fig. 1) show that the density
decreases with increasing aliphatic chain length.
The experimental data were fitted in the
nematic and isotropic phases with a quadratic
function obtained starting from the Landau - de
Gennes phenome-nological theory of the phase
transitions in nematic liquid crystals. The oddeven effect of the alkyl chain length on the
relative volume change (the left inset) is in
accordance with former findings. The second
inset of Fig. 1 illustrates the temperature
1.03
0.99
0.95
-20
3CB
4CB
5CB
6CB
7CB
8CB
-10
0
10
20
T-TNI, K
Fig. 1: Temperature dependence of the
density of some CBs in the nematic and isotropic
phases. Left inset: odd-even effect for the relative
volume changes. Right inset: temperature
variation of the density part depending on the
order parameter.
In situ infrared spectroscopic arguments
were given [2] that show monomer, dimer and
hydrogen bonded species of 8CB coexisting in
the so-called surface layer, their population
Selected Results
varies drastically as function of the temperature.
We focus on composites 8CB confined to
nanoporous molecular sieves of AlMCM-41
type with cylindrical pores of 4.6 nm diameter.
The spectra were collected (on pressed selfsupported pellets) with a Bruker IFS 66
spectrometer, in a cell connected to a standard
vacuum/adsorption installation, which allowed
sample heating. The resolution of the
spectrometers was set at 2 cm-1, at least 128
scans were accumulated. All the IR spectra were
analyzed using a fitting procedure based on the
least square method getting free all the
parameters.
Peak height, au
dimers
300
400
500
600
Temperature, K
2200
2220
2240
Peak height, au
monomers
2260
Wavenumbers, cm-1
623 K
598 K
573 K
548 K
523 K
498 K
473 K
448 K
423 K
398 K
373 K
295 K
2100
2150
300
400
500
600
Temperature, K
Peak height, au
H-bonded
2200
2250
Wavenumbers, cm-1
2300
300
2350
100
TG
composite
bulk
exo
400
500
600
540 K
Temperature, K
Fig. 2: FTIR spectra obtained in situ at
different temperatures as shown. The insets show
the spectra and their decomposition in the region
of the CN stretching.
Typical IR spectra are shown in Fig. 2:
These spectra are complex and contain peaks
due to both components. The Gaussian
components in the CN stretching region were
assigned as follows: “wide” 2226 cm-1 to bulklike dimers; 2235 cm-1 to hydrogen bonded
molecules (peak half-band widths are larger
than for bulk 8CB). Peak position shifts
downward by increasing temperature, while
their intensity generally decreases. The intensity
variation with the temperature is illustrated in
the insets of Fig. 2. H-bonded species disappear
at 500 K.
Weight loss, %
Peak height, au
dimers
monomers
H-bonded
Thermogravimetric (TG) measure-ments
(carried out using a Perkin Elmer Diamond
TG-DTA apparatus under dry flowing air at a
rate of 10 K/min) allowed estimating the 8CB
loading degree and the host-guest interactions
between 8CB molecules and the surface of
confining matrix.
TG-DTA curves of the composite are
reproduced in Fig. 3: several endothermal and
exothermal processes take place. The differences
between the composite and the bulk 8CB
consist especially in the shift toward higher
temperature for the first main exothermal peak
and in the height much bigger of the peak at
540 K for the composite. The peaks in DTG
curve are asymmetric showing that there are
several species contributing to the mass loss. A
new exothermal peak appears around 540 K on
DTA plot of composite without corresponence
in DTG curve, due to a thermal process
involving species bonded to the surface.
80
Surface
phenomena
endo
400
60
Temperature, K
600 800 1000
DTA
DTG
40
400
600
800
1000
Temperature, K
Fig. 3: TG/DTG and DTA curves for the
composite and in comparison with the
behavior of 8CB bulk (inset). DTA curves
were normalized to the 8CB amount.
References
[1] I. Zgura, R. Moldovan, T. Beica, S. Frunza,
Cryst. Res. Technol. 44, 883–888 (2009).
[2] L. Frunza, S. Frunza, M. Poterasu, T. Beica,
H. Kosslick, D. Stoenescu, Spectrochim.
Acta Part A 72, 248-253 (2009).
37
Selected Results
Search for novel intermetallic ternary compounds: a study of M2Pd14B5 system
with M = La, Ce, Pr, Nd, Sm, Eu, Gd, Lu and Th
Andrei Galatanu
collaboration work in the frame of COST – P16 "ECOM" action
To gain more insight into the general physical
behavior of rare earth–noble metal–non-metal
systems, our studies were extended to rare earth
palladium boride ternaries. In the present study,
it turned out that besides the well known
perovskite phases REPd3B1−x (RE is one of the
light rare earth elements) novel and hitherto
unknown compounds can exist near the
composition REPd7B2.5 for all light rare earth
elements from La to Gd. Furthermore the
investigation was extended to include the
actinoid elements. Novel ternary compounds,
RE2Pd14+xB5−y (RE = La, Ce, Pr, Nd, Sm, Eu, Gd,
Lu, Th; x ~ 0.9, y ~ 0.1), have been synthesized
by arc melting. The crystal structures of
Nd2Pd14+xB5−y and Th2Pd14+xB5−y were determined
from X-ray single-crystal data and both are
closely related to the structure type of
Sc4Ni29B10. All compounds were characterized
by Rietveld analyses and found to be isotypic
with the Nd2Pd14+xB5−y type. Measurements of
the temperature dependent susceptibility and
specific heat as well as the temperature and field
dependent resistivity were employed to derive
basic information on bulk properties of these
compounds. [1]
Complex analysis of the XRD paterns
revealed that the final structure in all its details is
closely related to the Sc4Ni29B10 type [2]. The
chemical formula turns out to be Nd2Pd14+xB5-y.
The crystal structure is presented in figure 1(a) in
a three-dimensional view along the [010] axis. As
one of the typical structural units for metal-rich
borides, B2 atoms are found in deformed
triangular prisms capped on one side by an
additional Pd atom whereas B1 atoms (defect
site) are in a coordination unit formed by two
trigonal prisms, face connected on a common
quadratic base and formed by seven palladium
atoms. Each rare earth atom is surrounded by six
palladium atoms and six neighboring palladium
38
atoms at a larger distance of 0.303 nm. Figure
1(b), volume versus rare earth, indicates a 3+
ground state for Ce and Sm. The monotonic
variation of both a and c parameters with rising
ordinal number of the rare earths is consistent
with a shrinking unit cell volume, i.e. the
lanthanide contraction. The minor increase of
the c/a ratio throughout the stability range of the
Nd2Pd14.9B4.9 structure type yields only a small
increase of the lattice anisotropy. In contrast to
the light rare earth analogs, the Eu-containing
compound indicates a strong positive deviation
from the unit cell volume variation versus the
rare earths, i.e. a valence state close to the
divalent Eu one.
Fig.1: (a) Three dimensional crystal structure
of Nd2Pd14+xB5−y. (b) Volume and c/a ratio
versus rare earth.
The temperature dependent electrical
resistivity ρ(T ) of RE2Pd15B5, RE = Ce, Pr, Nd,
Sm, Eu, Gd and Lu, is shown in figure 2 in a
normalized representation for temperatures
above 4.2 K. The electrical resistivity, ρ, of
RE2Pd15B5 is, in general, characterized by small
RRR values primarily caused by defects inherent
to the present crystal structure. The low
temperature resistivity behavior is distinguished
by a minimum in ρ(T) in the vicinity of 20 K
followed by an increase towards lower
temperatures. A non-magnetic-originlike variable
range hopping is conceivable due to statistical
disorder of atoms within the crystal structure, as
well as a magnetic origin from superzone
boundary effects above a magnetic phase
Selected Results
transition or from short range order effects above
Tmag. At first sight, magnetic correlations as the
origin seem more likely, since magnetic fields of
the order of several teslas completely suppress the
anomalies indicated above.
Fig. 2: The temperature dependent electrical resistivity
of RE2Pd15B5,
Fig. 3: Low temperature dependence of resistivity
for RE = Ce, Pr, Eu and Gd
Details of the low temperature resistivity are
shown for M = Ce, Pr, Eu and Gd in figure 3.
Obviously, the application of external magnetic
fields causes a suppression of the anomalies
associated with long range magnetic order in the
case of Ce and Gd, as well as the anomalies
linked to the non-magnetic ground state of the
Pr and the Eu system. The change of the
resistivity upon the application of magnetic fields
is extremely small. The only exception found in
the whole series is for Eu2Pd15B5, where the
application of 12 T at T = 2 K changes the
resistivity by about 10%. A rapid decrease of the
resistivity in the case of Gd2Pd15B5 below the
maximum at about 6 K results from the onset of
long range magnetic order and is in agreement
with magnetization and heat capacity
measurements. The fact that the Lu based
compound as well as the systems having nonmagnetic ground states, i.e., Pr and Nd, would
be equally likely suggests a non-magnetic origin
of the resistivity increase observed towards low
temperatures. A proof of this proposition in
terms of Mott’s variable range hopping
mechanism [3] is difficult because of the
extremely small changes of the absolute resistivity
values of these compounds. Summarizing, the
crystal structure of novel ternary compounds
RE2Pd14+xB5−y (RE = La, Ce, Pr, Nd, Sm, Eu, Gd
and Th) was determined from x-ray single-crystal
data and was found to be closely related to the
structure of Sc4Ni29B10 with tetragonal unit cell
and space group type I 41/amd. All rare earth
homologs were characterized by Rietveld analyses
and found to be isotypic with the Nd2Pd15B5
type. Physical properties are primarily
determined by two effects: (i) the magnetic
moment of the respective rare earth ion and
associated CEF effects; (ii) intrinsic defects of the
crystal structure. Clear evidence for long range
magnetic order is found for Gd2Pd15B5, while
solid indications of magnetic ordering are found
for the Ce, Nd and Sm systems. The shrinking
unit cell volume, when proceeding from
Ce2Pd15B5 to Gd2Pd15B5, modifies the RKKY
interaction
such
that
antiferromagnetic
interactions (θp < 0) gradually change to
ferromagnetic ones (θp > 0) and as a
consequence, Gd2Pd15B5 orders ferromagnetically
at TC = 6.5 K. Due to CEF effects, Pr2Pd15B5 is
non-magnetic at low temperatures, while
Eu2Pd15B5 is dominated by spin fluctuations
driven by the intermediate valence state of the
Eu ion.
References
[1] E Royanian, E Bauer, H Kaldarar,
A Galatanu, R T Khan, G Hilscher,
H Michor, M Reissner, P Rogl, O Sologub,
G Giester and A P Goncalves J. Phys.:
Condens. Matter 21 (2009) 305401
[2] Y. B. Kuz’ma , O M Dub , V A Bruskov,
N Chaban and L V Zavalii, Kristallografiya
33 (1988) 841
[3] N. F. Mott N 1970 Phil. Mag. 22 (1970)
39
Selected Results
Specificity of defects induced in silicon by RF-plasma hydrogenation
C. Ghica, L. C. Nistor, M. Stefan, D. Ghica, B. Mironov
in cooperation with
S. Vizireanu, A. Moldovan, M. Dinescu
National Institute for Laser, Plasma and Radiation Physics, Bucharest-Magurele, Romania
Hydrogen related defects in silicon are still a
subject of interest related to their direct
involvement in the SOI (Silicon-on-Insulator)
device fabrication based on the "smart-cut"
technique [1].
Single crystal Si wafers have been submitted to
hydrogen RF-plasma treatments using a 13.56
MHz RF generator. The hydrogen partial pressure
has been varied in the 10-104 Pa range and the
discharge power between 50-150 W. TEM
observations have been performed at NIMP on a
JEOL 200 CX electron microscope and at EMAT University of Antwerp, on a JEOL 4000 EX
microscope on specimens prepared at NIMP by
mechanical thinning and ion milling on a Gatan
PIPS machine. The Electron Paramagnetic
Resonance (EPR) experiments were performed at
NIMP with an X-band (9.4 GHz) EMX-Plus
Bruker spectrometer. The EPR spectra were
recorded in the 120 to 295 K temperature range,
using a Bruker ER 4131VT cryogenic system.
There are two kinds of effects of the hydrogen
RF-plasma treatment on Si wafers: surface
corrugation and formation of defects.
Fig. 1a shows a typical diffraction contrast
image of the {111} defects found in our plasma
hydrogenated Si samples. The defects have an
intrinsic character (missing silicon plane), as we
have demonstrated from the diffraction contrast
behavior [2]. Typical HRTEM images of the {111}
planar defects (Fig. 1b) reveal the defect as a sharp
phase-contrast variation in the defect plane. The
defect is not strictly limited to a single {111} plane,
but it migrates to adjacent {111} planes forming
jogs. The structural model that we proposed for the
{111} defects in hydrogenated silicon involved Si
dangling bonds that could be partially saturated
with hydrogen.
40
Fig. 1. (a) Bright-field TEM image of a {111} planar
defect; (b) HRTEM images of {111} planar defects in
hydrogenated Si showing jogs along a {111} defect and
defect migration to adjacent planes.
A second category of defects introduced by RFplasma hydrogenation in silicon are the planar
defects oriented along {100} planes, not occurring
in diamond cubic materials. The diffraction
contrast of a typical {100} planar defect in
hydrogenated Si is presented in Fig. 2a. The defect
is bordered by a dislocation loop. The fringes
inside the dislocation loop indicate the presence of
a planar defect with a characteristic displacement
−
vector oriented perpendicular to the (00 4)
reciprocal vector. We have shown [3] that the
limiting dislocation loop has a prismatic character.
The HRTEM image of a fragment from the central
region of a (001) defect in edge-on orientation is
imaged in Fig. 2b. The defect has a diffuse aspect
affecting two or three neighboring (001) planes. It
has not a unique extrinsic or intrinsic character,
but rather a mixed one, resulting from the
Selected Results
accumulation of vacancies and self-interstitials on a
{001} plane.
Fig. 2. (a) Bright-field image of a (100) planar defect
limited by a dislocation loop around a planar defect;
(b) HRTEM image of an (001) defect.
Our TEM observations revealed also the presence
of voids in the plasma treated samples. They appear
as agglomerations of voids (5-20 nm size) and they
are surrounded by long range strain field. Fig. 3
shows a two-beams image of the defect in a planview specimen prepared from a hydrogenated
Si(001) wafer.
The EPR spectrum at 120 K consists of two
isotropic lines with different line widths.
We attribute the narrow EPR line at higher
magnetic field (∆Hpp=0.095 mT, g=1.9995) to
conduction-band electrons in Si, thermally released
from hydrogen induced defect levels in the gap.
The broader line at lower magnetic field
(∆Hpp=0.68 mT, g= 0.0066) moves to higher
values of magnetic field with temperature increase.
This signal could be assigned to Si dangling bonds
in the amorphous Si resulting from the surface
SiOx reduction during the H-plasma treatment.
This work has been supported by CNCSIS in the
frame of the PN II Ideas national research program
(Project No. 233/2007).
References
[1] M. Bruel: Nucl. Instrum. Meth. B 108, 313,
(1996)
[2] C. Ghica, L.C. Nistor, H. Bender,
O. Richard, G. Van Tendeloo,
A. Ulyashin: Philos. Mag. 86, 5137 (2006)
[3] C. Ghica, L.C. Nistor, H. Bender, O.
Richard, G. Van Tendeloo, A. Ulyashin: J.
Phys. D: Appl. Phys. 40, 395 (2007)
[4] C. Ghica, L. C. Nistor, M. Stefan, D. Ghica,
B. Mironov, S. Vizireanu, A.
Moldovan and M. Dinescu, Appl. Phys. A
DOI: 10.1007/s00339-009-5527-1
(accepted 200
Fig. 3. TEM image of a cluster of bubbles
and the surrounding long-range strain field
in hydrogenated Si.
41
Selected Results
Vortex pinning in the noncentrosimetric superconductor CePt3Si
C.F. Miclea, C. Miclea
in cooperation with
A. C. Mota , M. Nicklas, R. Cardoso, F. Steglich
Max-Planck-Institute for Chemical Physics of Solids, 01187 Dresden, Germany
Heavy-fermion superconductor CePt3Si [1]
reveals extremely slow flux dynamics with creep
rates even lower than those in Sr2RuO4,
PrOs4Sb12 and UPt3 [2]. CePt3Si is a member of
a whole class of presumably unconventional
heavy-fermion superconductors such as CeRhSi3
[3] CeIrSi3 and UIr whose crystal lattices do not
posses an inversion center. In CePt3Si
antiferromag-netic order sets in at a Néel
temperature TN=2.2 K while the system adopts a
super-conducting ground state below a transition
temperature Tc=0.75 K. The high quality
CePt3Si single crystal investigated was grown
using a Bridgman technique and the sample was
oriented, cut, and polished in a parallelepiped
shape with the dimensions 4.60 mm/2.65
mm/1.05 mm. The longer dimension is parallel
to the crystal a axis and the smaller one is parallel
to the b axis.
The investigation of vortex dynamics was
performed in a dilution refrigerator in the
temperature range 0.1≤T≤0.5 K with the sample
enclosed in a custom-built mixing chamber and
using a superconducting quantum interference
device (SQUID) detector to determine the
magnetic flux expelled. In the same experimental
configu-ration, ac susceptibility experiments were
performed
in
the
temperature
range
0.025≤T≤2.4 K using an inductance bridge with
a SQUID as null detector. A very low ac
excitation field of H=1.3 mOe was applied along
the a axis at a frequency f =80 Hz. Both, the real
χ’ and the imaginary χ’’ parts of the ac
susceptibility (Fig.1) reveal the superconducting
transition with the midpoint of the anomaly in
χ’ located at Tc=0.45K. The transition into the
antiferro-magnetically ordered state is visible as a
sharp peak at TN=2.3 K, a value consistent with
the one obtained in previous specific-heat
studies. Upon further cooling down, the system
42
adopts a superconducting ground state at
Tc=0.42 K. Both TN and TC are defined as the
midpoint of the jump in C across the respective
anomaly.
Fig.1 Temperature dependences of the real and
imaginary part of the ac magnetic susceptibi-lity across
the superconducting phase transition.
Isothermal relaxation curves of the remnant
magnetization Mrem were taken after cycling the
specimen in an external dc magnetic field H
applied along the crystallographic a direction. In
Fig.2, we present the temperature dependence of
the remnant magnetization obtained after cycling
the sample in a field of H = 500 Oe.
Fig. 2. Temperature dependences of the total remnant
magnetisation. Dashed line is a liniar fit to the data.
Inset: Mrem at T=0.1K and T=0.2K
versus external field H.
Selected Results
The temperature dependence of the normalized relaxation rates S=∂ln(M)/∂(lnt) for CePt3Si
is depicted in Fig. 3 together with the rates
obtained for the heavy-fermion superconductor
UBe13 [2] which violates time-reversal symmetry.
Remarkably, CePt3Si has anomalously small
decay rates comparable with Li2Pt3B and lower
by a factor of five than the very low creep rates
observed in PrOs4Sb12.
noncentrosymmetric super-conductors and yield
a very strong flux-line pinning due to the
fractionalization of vortices. So twin boundaries
could act as planar barriers for flux flow without
affecting the critical current. While this could be
an explanation for the observed behavior in
CePt3Si and also provides a possible mechanism
for the flux avalanches reported for Li2Pt3B [4]
there has been no direct observation of such fluxline pinning on twin boundaries so far.
Fig. 4. Comparison of the normalized relaxation rates
S=∂ln(M)/∂(lnt) and the critical current at T=0.3 K for
different compounds. For each compound the left bar
depicts S and the right jc.
Fig. 3. Comparison of the normalized relaxation rates
S=∂ln(M)/∂(lnt) versus temperature for different
compounds in a log-log representation.
In general in superconductors with strong
vortex pinning the critical current jc is high.
However, this is not the case in CePt3Si
which has the lowest critical current
[jc(300mK)]=1.8x107A/m2] among the compared
superconductors (Fig. 4).
The extremely slow vortex dynamics in
CePt3Si in combination with the comparatively
small critical current suggests that an unconventional and very effective pinning mechanism is at
work. Similar effects had been seen in UPt3,
Sr2RuO4, and PrOs4Sb12 and have been
associated with an intrinsic pinning mechanism
on domain walls.
However, CePt3Si does not break timereversal symmetry. It has been recently proposed
by Iniotakis et al. [3] that twin boundaries in
twinned crystals could play a similar role in
In conclusion, we observed extremely slow
vortex dynamics in the noncentrosymmetric
CePt3Si in spite of a very low critical current.
The relaxation rates are comparable only to the
similarly noncentro-symmetric Li2Pt3B which
has as well a modest critical current though larger
than in CePt3Si. This apparent contradiction of
extremely low relaxation rates in conjunction
with low critical currents indicates an
unconventional and very effective flux trapping
mechanism in CePt3Si.
References
[1] E. Bauer et al., Phys. Rev. Lett. 92, 027003
(2004).
[2] A. Amann, et al., Phys. Rev. B 57, 3640
(1998).
[3] C. Iniotakis, S. Fujimoto, and M. Sigrist,
J. Phys. Soc. Jpn. 77, 083701 (2008)
[4] C.F. Miclea et al., Phys. Rev. B 80, 132502
(2009)
43
Selected Results
Geometrical effects and signal delay in time-dependent transport at the nanoscale
V. Moldoveanu
joint work with
A. Manolescu
Reykjavik University, School of Science and Engineering , Kringlan 1, IS 103 Iceland
and
V. Gudmundsson
Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavik, Iceland
One of the main features of mesoscopic
systems is that their geometry leaves some
fingerprints on the transport properties (e.g. the
invasive role of the current probes). In this work
[1] we have described theoretically the timedependent transport through such structures
within the reduced density matrix formalism
borrowed from quantum optics. When extended
to open quantum systems this method is a
powerful tool for studying electron dynamics
through a sample coupled to biased leads and
characterized by a well defined initial state.
We complement previous approaches [2,3,4]
in the following way: i) the generalized master
equation GME is solved without the Markov
approximation, for arbitrary time-dependent
coupling to the leads; ii) the usual assumption
that the spectrum of the sample is entirely
contained into the bias window is not needed; iii)
the transfer Hamiltonian describing the coupling
between the leads and the sample takes into
account the localization of the sample states
depending on the geometry of the sample and on
the region where the leads are plugged.
The GME is solved using the Crank-Nicolson
algorithm. In real experiments the sample is
characterized either by a ground state or by a lowenergy excited state and for small couplings to the
leads one expects that most of the levels below
(above) the bias window remain occupied (empty)
and will not contribute to the current. The
relevant many-body states are actually few and
they are given by all combinations of occupation
numbers for a bunch of single particle states from
the vicinity of the bias window. Therefore one can
actually restrict the calculation of the matrix
elements for the RDO.
44
The numerical simulations are obtained for a
lattice Hamiltonian. As a main application of the
method we have computed the transients
associated to each level of a 2D lattice in the
presence of a strong perpendicular magnetic field.
The lattice contains 5x10 sites which is large
enough to exhibit the well known Hofstadter
spectrum. In this case the currents are carried only
by edge states and depend both on the contact
point and on the topology of the state. Different
initial states of the isolated system lead to different
transients but to the same steady-state current
which is not achieved at the same time. We have
presented a comprehensive analysis of the electron
dynamics in the transient regime and also studied
the relevant matrix elements of the RDO (both
populations and coherences are discussed). The
details of the electron dynamics can be extracted
from the currents associated to each level. In
Fig.1(a) we compare the transients in both leads
associated to the 2 levels within the bias window
(there are 4 levels within the active window).
We include as well the currents in the right
lead when the left lead is disconnected (the two
curves corresponding to the labels in the lower
right corner of the figure). Electrons from both
leads can tunnel from or into these states and the
difference between the chemical potentials leads
eventually to equal currents in the steady state. In
the transient regime the currents in the two leads
behave however differently: the current in the left
lead increases abruptly at short times with a bigger
slope for the level whose coupling to the contact is
stronger, while the current flowing into the right
lead is delayed. Moreover, this delay depends on
the state which carries the current.The 3rd level
starts to transmit charge earlier while the 2nd
Selected Results
needs more time to inject electrons into the right
lead (for t~20).Fig.1(b) gives the currents passing
through the 1st and 4th level, which are outside
the bias window. The following features are
noticed: i) The lowest level absorbs charge from
both leads; ii) The currents decrease slowly to zero
giving no contribution to the steady-state current;
iii) The current of the 4th level which is located
slightly above the bias window oscillates with
both positive and negative values because in the
transient regime this level can gain or loose charge
as well. One can also see that the steady state
regime is reached faster by the two states located
within the bias window.
Also we have shown that the Markov
approximation is appropriate for steady-state
calculation but misses some memory effects in the
transient regime. We want to emphasize that our
method not only goes beyond the Markov and
wide-band approximations, being thus from the
very beginning more accurate, but it is even more
efficient for numerical calculations: the time
integration can be done recursively, which is not
possible in the Markov approximation.Further
expected applications of this method include
pulse propagation [5].
Fig. 1 (a) The currents transmitted through the
states below the bias window (2nd and 3rd). (b) The
currents associated to the two states below and above
the bias window (1st and 4th).
References
[1] Moldoveanu V, Manolescu A, Gudmundsson
V., New Journal of Physics 11, 073019
(2009).
[2] Gurvitz S A, Prager Ya S, Phys. Rev. B 53
15932 (1996).
[3] Harbola U, Esposito M, and Mukamel S,
Phys. Rev. B 74, 235309 (2006).
[4] Pedersen J N, Wacker A, Phys. Rev. B 72,
195330 (2005).
[5] Moldoveanu V., Manolescu A.,
Gudmundssson V., Physical Review B 80,
205325 (2009).
45
Selected Results
In-depth investigation of EPR spectra of Mn2+ ions in ZnS single crystals
with pure cubic structure
S. V. Nistor and M. Stefan
The remarkable optical properties exhibited
by the cubic ZnS nanocrystals doped with
manganese (cZnS:Mn) resulting in the dramatic
increase in both quantum luminescence efficiency and lifetime shortening compared to the
bulk ZnS [1], have lead to intensive research on
the dopant localisation and related host structural properties. Electron Paramagnetic Resonance
(EPR) spectroscopy is the method of choice for
such studies, due to its ability to detect small
changes in the local crystal field resulting from
different localisations of the paramagnetic impurity ions and/or changes in the configuration and
nature of the neighbouring ligands.
The determination of such configuration
variations as well as the separation of the bulk
and surface properties from the quantum
confinement effects in nanocrystalline ZnS
requires accurate reference EPR spectrum
parameter values for the bulk material. However,
the various sets of spin Hamiltonian (SH)
parameters for Mn2+ ions in bulk ZnS crystals
previously reported in the literature [2] exhibit
rather large variations, comparable to the
variations in the corresponding values for
nanocrystalline ZnS [3]. Thus, the interpretation
of the EPR spectra becomes questionable, as the
variations in the SH parameters attributed to
changes in the local crystal field due to different
localisations of the Mn2+ ions in the ZnS
nanostructures might be just the result of
experimental errors.
Besides a more accurate set of reference SH
parameters for the cubic ZnS crystals, further
substantial advance in understanding the
properties of Mn2+ ions in ZnS nanocrystals is
conditioned by a higher accuracy in determining
the SH parameters of the observed spectra,
including the zero field splitting parameters.
Such accuracy cannot be achieved without
including both forbidden hyperfine transitions
46
and line broadening mechanisms in the EPR
spectra line shape simulations used in determining the SH parameters for paramagnetic ions in
nanomaterials. The corresponding reference
information for Mn2+ ions in bulk crystalline
ZnS was not available in the scientific literature.
The present research intended to fill up this
informational gap, by reporting the results of a
detailed X (9.8 GHz)-band EPR investigation of
the substitutional Mn2+ ions in well oriented
ZnS single crystals with pure cubic structure.
The investigations were performed on purely
cubic ZnS single crystals of high perfection,
undoped and nominally doped with 0.5%
MnCl2, grown by the gradient technique in
PbCl2 melt [4]. The EPR measurements were
carried out at room temperature on an X
(9.8 GHz)-band spectrometer which is part of
the Research Centre for advanced ESR
techniques (cetRESav) equipment.
The resulting EPR spectra (Figure 1) were
analyzed using specialized computer programs
for the analysis and simulation of the EPR
spectra, based on a straightforward diagonalization of the spin Hamiltonian energy matrix.
Highly accurate SH parameters: g =
2.00225 ± 0.00006; a = (7.987 ± 0.008) x 10-4
cm-1 and A = -(63.88 ± 0.02) x 10-4 cm-1 were
obtained by simulation and fitting to the
experimental allowed transitions recorded for the
magnetic field aligned within ± 0.25 degrees
accuracy along the main crystal axes. The
resulting set of parameters describes the observed
EPR line positions within the experimental error
of 0.01 mT (see Figure 1).
The
normally
forbidden
hyperfine
M = +1/2 ↔ -1/2, ∆m = ±1 transitions were also
observed, for the first time in this crystal lattice
host. Their position was found to be in
agreement, within the experimental accuracy of
∆H = ± 0.01 mT, with calculated positions
Selected Results
using the same SH parameters. The angular
variation of the intensities ratio of the central
forbidden to the allowed transitions could be
accounted for only by including an additional
constant contribution comparable to the largest
theoretical value.
(b)
(c)
(d)
c-ZnS:Mn2+
H in (110)
100
2+
ZnS:Mn
H || <001>
(a)
330
80
340
350
360
370
Magnetic field (mT)
θ (deg)
60
40
20
x 0.5
001
0
340
350
360
370
Magnetic field (mT)
Fig. 1 The angular dependence of the EPR
transitions of the Mn2+ ions in cubic ZnS single
crystals for the rotation of the magnetic field away
from <001> in a (110) plane. Dashed lines
correspond to allowed transitions and dot and
dashed lines to the hyperfine forbidden ∆m = ±1
transitions.
We have also shown that the observed line
broadening of the M = ±1/2 ↔ ±3/2 and
±3/2 ↔ ±5/2 fine structure transitions (see Fig.
2) can be explained by considering small
fluctuations in the fourth order crystal field
parameter a and small variations around the zero
value in the axial field parameter D, which are
present even in the highest quality cubic ZnS
single crystals. The same mechanism also
explains the absence in the observed EPR
spectrum of the Mn2+ doped ZnS single crystals
of the non-central M = ±5/2 ↔ ±3/2, ∆m = ±1
and M = ±3/2 ↔ ±1/2, ∆m = ±1 hyperfine
forbidden transitions, which, according to
calculations, are comparable in intensity with the
corresponding central transitions.
The analysis offers for the first time an
insight into the line broadening mechanisms
acting on the Mn2+ ions in the bulk crystalline
ZnS, mechanisms which are even more
important in the nanocrystals.
Fig. 2. (a) The experimental EPR spectrum of the
Mn2+ ions in undoped ZnS crystals for H || <001>;
(b). The simulated spectrum for a Lorentzian
lineshape, without considering line broadening
effects; (c) considering a Gaussian distribution of
the cubic ZFS parameter a with the standard
deviation σ(a) = 1.4 x 10-7 cm-1; (d) including a
Gaussian distribution of the axial ZFS parameter
D with standard deviation σ(D) = 1.3 x 10-5 cm-1
as well.
The reported data offer the necessary basis
for an improved analysis of the EPR spectra of
Mn2+ ions in ZnS quantum dots/nanocrystals,
which is expected to lead to a better
understanding of their local atomic and
quantum confinement related properties.
This work has been published in Journal of
Physics: Condensed Matter 21 (14), 145408
(2009).
References
[1] H. Hu, W. Zhang, Opt. Mat. 28, 536
(2006) and references cited therein
[2] J. Kreissl, phys. stat. sol. (a) 97, 191 (1986)
and references cited therein
[3] P. A. Gonzalez Beerman, B. R. McGarvey et
al., J. Nanopart. Res. 8, 235 (2006) and
references cited therein
[4] L. C. Nistor, S. V. Nistor, M. I. Toacsan,
J. Cryst. Growth 50, 557 (1980)
47
Selected Results
Radiation induced point- and cluster-related defects with strong impact
to damage properties of silicon detectors
I.Pintilie
in cooperation with
E. Fretwurst, A. Junkes and G. Lindström
Institute for Experimental Physics, University of Hamburg, Hamburg, Germany
48
investigated diodes was measured by means of C-V
and I-V diode characteristics while the “microscopic”
defect analysis was achieved using the Thermally
Stimulated Current (TSC) technique. From the
multitude of defects detected by TSC only few
influence the operation of Silicon detectors at ambient
temperatures. These are:
Point defects: i) The Ip center - a point defect formed
via a second order process that can be associated with
the long searched for V2O complex or with a Carbon
related center, responsible for the observed type
inversion effect in Oxygen lean material after γirradiation [1,2]. The quadratic dose dependence of
the Ip center is evidenced both for the STFZ and
DOFZ diodes - see Fig.1a. Ip contributes with negative
space charge to Neff and has thus a direct influence on
Vfd (see Fig.1b).
0.0
b)
-5.0x1011
∆Neff (cm-3)
One of the most challenging applications for silicon
detectors is given by their use in the inner tracking
region of forthcoming colliding beam experiments.
The required detector properties have to be guaranteed
even after irradiation with up to hadron fluences of
several 1016cm-2 and the detectors will encounter long
term and rather complex operational scenarios. The
limiting factors for their practical application are the
radiation induced changes in the effective doping
concentration (Neff) resp. full depletion voltage (Vfd),
the dark current and the degradation in the charge
collection efficiency. These device properties are
subject to changes not only during irradiation but also
during beam-off periods. Especially the long term
annealing effects in Neff increase the initially observed
damage effects and therefore they are of extreme
importance envisioning extended operation periods of
several years. Any promising defect engineering for a
possible radiation hardening of the material as well as
improvements by modifying the detector processing
will rely on a thorough knowledge of the generation of
electrically active defects which are responsible for the
observed changes in the macroscopic device properties.
This goal is addressed in our work by focusing on a
detailed investigation of specific damage induced
defects (point- and cluster-related), which proved to
have an impact on the device performance. Five
different kinds of silicon material, presently discussed
as candidates in the foreseen applications, have been
investigated for this purpose: standard float zone
(STFZ), Oxygen enriched FZ (DOFZ), magnetic
Czochralski (MCz) and thin epitaxial layers grown on
Cz substrates, standard (EPI) and Oxygen enriched
(EPI-DO). To distinguish between point and cluster
related defects, damage effects have been investigated
after irradiation with Co60- γ rays (up to doses of 500
Mrad), 23 GeV protons (up to a fluence of 6·1014cm-2)
and 1 MeV equivalent reactor neutrons (5·1013cm-2).
The “macroscopic” device performance of the
-1.0x1012
-1.5x1012
from C-V
DOFZ
STFZ
predicted (TSC)
DOFZ (errors > 5%)
STFZ (errors < 5%)
-2.0x1012
-2.5x1012
-3.0x1012
0
50 100 150 200 250 300 350 400 450 500 550 600
Co60- gamma irradiation dose
Fig. 1: γ-dose dependence of: a) the Ip and BD defect
concentrations; b) the change of Neff in both STFZ and DOFZ
Si-FZ diodes.
Due to its mid-gap acceptor level it also contributes
significantly to the leakage current. Ip is stable up to
Selected Results
temperatures of 3500C. As a point defect it is strongly
generated after γ-irradiation but was also detected after
23GeV proton damage [3].
ii) The BD center - a bistable donor (point defect)
created during irradiation, strongly generated in
Oxygen rich material (see Fig.1a). It was associated
with one of the earlier thermal donors in Si [2-4]. It is
the cause for the effective positive space charge
induced by gamma irradiation in Oxygen rich Si
diodes (see Fig.1b). Except for the Oxygen lean STFZ
material, the BD is detected in all other materials,
independent of the type of irradiation.
TSC signal (pA)
120
a)
E(30K)
H(40K)
90
VO
60
H(152K)
H(140K)
30
EPI-DO 75 µm
Fw- as irradiated
Fw - 20min
Fw - 80 min
Fw - 160 min
Fw - 320 min
Fw - 640 min
Fw - 1280 min
Fw - 2810 min
Fw - 5700 min
Fw - 11460 min
Fw - 16980 min
V2
?
H(116K)
BDA0/++
0
0
20
40
60
80
100 120 140 160 180 200
Temperature (K)
Fig. 2: TSC spectra after proton irradiation as function
of annealing at 80°C;
75 µm EPI-DO, 1 MeV-eq. n-irradiation, Φ eq = 5.0E13/cm²
1.0E+13
macr. measured (C/V)
∆Neff = Neff0 - Neff(Φ ,t) [1/cm³]
macr. predicted (TSC)
a)
8.0E+12
6.0E+12
References
4.0E+12
donor generation small:
9.0E11/cm³, g = 1.8E-2/cm
2.0E+12
0.0E+00
1.0E-01
1.0E+00
1.0E+01
1.0E+02
1.0E+03
1.0E+04
1.0E+05
annealing time @ 80C [min]
75 µm EPI-DO, 23 GeV p-irradiation, Φ eq = 2.3E14/cm²
∆Neff = Neff0 -Neff (Φ,t) [1/cm³]
2.5E+13
b)
Cluster related defects: A group of four cluster related
defects determine the annealing effects seen after
hadron irradiation:
i) H(116K), H(140K) and H(152K) - with acceptor
levels in the lower part of the gap [5] (see Fig.2). These
hole traps contribute fully with negative space charge
to Neff and are responsible for the long term annealing
as seen by the increase of the depletion voltage (so
called “reverse annealing”). Their formation is not
affected by the Oxygen content or Si growth
procedure suggesting that they are complexes of multivacancies located inside extended disordered regions;
ii) E(30K) – with a donor level in the upper part of the
gap. This center contributes in its full concentration
with positive space charge to Neff and consequently is
responsible partly for the so called “beneficial
annealing” effect.
The TSC defect investigations were used to
predict the annealing effects of Neff and to compare the
results with values determined from C-V
measurements at room temperature – see e.g. Fig.3
(example after neutron and proton irradiation of EPIDO test diodes).
It is for the first time when a direct correlation
between the annealing behaviour of hadron irradiated
Silicon diodes as seen at “macroscopic scale” can be
understood by the “microscopically” investigated
formation of defects.
macr. measured (C/V)
2.0E+13
macr. predicted (TSC)
1.5E+13
1.0E+13
5.0E+12
donor generation large:
2.1E13/cm³, g = 9.0E-2/cm
0.0E+00
1.0E-01
1.0E+00
1.0E+01
1.0E+02
1.0E+03
1.0E+04
1.0E+05
annealing time @ 80°C [min]
Fig.3: Comparison between C/V measurements and predictions
as given by TSC results after irradiation with:
a) neutrons; b) protons.
[1] I. Pintilie, E. Fretwurst, G. Lindstroem and J. Stahl,
Appl. Phys. Lett. 82, 2169 (2003);
[2] I. Pintilie et al , Nucl. Instrum. Meth. Phys. Res. A
514, 18 (2003);
[3] I. Pintilie, M. Buda, E. Fretwurst, G. Lindström, J.
Stahl, Nucl. Instrum. Meth. Phys. Res. A 556, 197
(2006);
[4] E. Fretwurst, F. Hoenniger, G. Kramberger, G.
Lindstroem, I. Pintilie and R. Roeder, Nucl. Instrum.
Meth. Phys. Res. A 583, 58 (2007);
[5] I. Pintilie, E. Fretwurst and G. Lindstroem, Appl.
Phys. Lett. 92, 024101 (2008)
[6] I. Pintilie, E. Fretwurst, A. Junkes, G. Lindström,
Nucl. Instrum. Meth. Phys. Res. A 611, 52-68 (2009)
[7] I. Pintilie „Radiation induced point- and cluster –
related defects with strong impact to damage properties
of silicon detectors” Invited contribution at
International Nuclear Atlantic Conference, Rio de
Janeiro, Brazilia, 27th Sept. – 2nd Oct., 2009.
49
Selected Results
First principles study of oxygen vacancy-induced magnetic moments in TiO2
N. Plugaru
in cooperation with
R. Plugaru
IMT Bucharest, PO-BOX 38-160, Bucharest, Romania
and
M. Artigas
CPS, Universidad de Zaragoza, 50018 Zaragoza, Spain.
The role of oxygen vacancies (OVs) in the onset
of local magnetic moments in anatase and rutile
titanium dioxide (TiO2) has been investigated by
first principles electronic band structure
calculations. Our objectives have been to explain
the conditions of OVs-driven magnetism in
TiO2 phases, and tentatively, to outline a
practical route to control ferromagnetism (FM)
in TiO2 -based materials [1].
We performed total energy and band
structure calculations in the Local (Spin) Density
Approximation (LSDA) using the Full Potential
Local-Orbital (FPLO) code [2]. The exchange
and correlation potential was treated in the
parameterization of Perdew and Wang 92.
Supercell calculations were carried out at 200
irreducible k-points in the Brillouin zone. Several
supercells, see Fig.1 and Table 1, were built up
of anatase and rutile unit cells at equilibrium
volume. In these structures Ti ions are in
octahedral coordination (apically elongated
distorted oxygen octahedra) and there are three
in-plane Ti nearest neighbors (nn) to an O ion.
The defect configurations were chosen to
simulate such cases as listed in Table 1.
Fig.1 Illustrative supercells: A04 and R04.
50
Table 1. Supercell structures, OVs fraction and
configurations, planes of Ti nn to OVs and the
magnetic moment per supercell1).
Supercells
OVs
(%)
Configuration
Planes
Ti nn
µB/
supercell
A01
3.13
isolated
(100)
0.23
A02
6.25
isolated
0.05
A04
6.25
A05
9.38
chain along
[100]
cluster
(100)
(010)
(100)
0.00
R01
3.13
isolated
(100)
(010)
(-110)
R02
6.25
isolated
0.00
R03
6.25
R04
6.25
isolated
pairs 2)
isolated
pairs 3)
(-110)
(110)
(-110)
(-110)
(110)
0.00
0.28
0.00
1.09
unrelaxed lattice. 2)d= 2.51 Å , 3)d= 2.76 Å.
1)
In TiO2-δ phases the defect band appears in the
L(S)DA gap, close to the CB bottom, consistent with the donor nature of OV, see, e.g, the
density of states (DOS) plotted in Figs. 2 and 3.
The defect band is formed of mainly Ti 3d states
of the Ti ions nn to the vacancy. Our results
evidence a correlation between the onset of local
magnetic moments and the lattice stress
anisotropy in the defect vecinity. Thus, in the
unrelaxed lattice, the stress due to OVs is mainly
confined in the plane defined by the three Ti nn
to the defect. The O atoms are located on mirror
planes parallel to the main symmetry axis, i.e.
{-110} and {110} in rutile and {100} and {010} in
Selected Results
anatase. A magnetic moment may appear in
those unrelaxed structures in which all the mirror
planes of the OV sites are parallel to each other
(Figs.2 and 3). The magnetic moments are
localized at the Ti sites that contribute to the
defect states.
(Fig.4). The Ovs modify the oxygen coordination at the Ti sites: thus, Ti13 is surrounded by
five O2- in a square-pyramidal coordination,
whereas Ti5 has four O2- with a fourfold seesaw
coordination. The average Ti-O distances are
1.90 Å for Ti5 and 1.84 Å for Ti13. The
individual magnetic moments are significantly
higher for the 4-coordinated Ti5 (0.41 µB) than
(0.10 µB). This
difference may be explained by the higher degree
of covalency at the Ti13, in agreement with its
coordination number being higher and average
Ti-O bonds being shorter than in the case of Ti5.
The gross part of the magnetic moment is due to
the exchange split, partially occupied defect
band.
for the 5-coordinated Ti13
Fig.2 Anatase TiO1.875, structure A04: Site and
angular momentum-projected DOS.
Fig.3 Rutile TiO1.875, structure R03: Total, site
(Ti5) and l-projected DOS, upper panel; Total, site
(Ti13) and l-projected DOS, lower panel.
However, no magnetic moment appears in the
unrelaxed structures in which not all the mirror
planes of the OV sites are mutually parallel. The
onset of a magnetic moment is not likely to be
related to OVs concentration, as proven by the
data for structures A02 and A05 in Table 1 The
magnetic moments vanish by effecting the
relaxation of the lattice (see, e.g., structure R03,
in Fig.4). The relaxation has been carried out by
shifting the positions of the three Ti nearest
neighbors of the vacancy site. A null magnetic
moment and a non magnetic ground state are
obtained for Ti nn displacements d= 0.155 Å
Fig.4 Upper panel: Rutile R03 showing the
relaxation plane (-110). Note: the red lines stand
for Ti-O bonds in the equatorial plane of the MO6
octahedron and the blue lines stand for the Ti-O
apical bonds. Lower panel: Total and site-projected
DOS after relaxation of the Ti nn positions.
References
[1] R. Plugaru, M. Artigas and N. Plugaru, EMRS 2009 Spring Meeting, Symposium H,
Strasbourg, France, June 8-12 2009
[2] K. Koepernik and H. Eschrig, Phys. Rev. B
59 (1999) 1743.
51
Selected Results
Kondo peaks and dips in the differential conductance of a multi-lead quantum dot:
Dependence on bias conditions
Mugurel Tolea, Ion Viorel Dinu, Alexandru Aldea
The observation of the Kondo effect in quantum
dots allows a direct insight on this interesting
many-body effect, whose experimental fingerprint is the enhanced differential conductance at
zero bias which is a specific type of zero-bias
anomaly. The great advantage over the bulk
Kondo effect is of course the possibility to
control the parameters like, for instance, the
coupling with the leads. Next, it was shown that
even more information can be extracted if the
dot is connected to three leads. The three leadKondo problem was theoretically considered
before in, e.g.,[1], and experimentally realized by
Leturcq et al[2] The third lead was used to read
the nonequilibrium density of states (DOS)
induced by the other two leads.
In this paper, we show that the multi-lead
geometry exhibits a complex conductance
behavior as function of the bias applied on the
leads. For asymmetrically applied bias, the
conductance in one of the leads may show a
minima at zero bias, instead of the usual
maximum in the Kondo regime. More
importantly, the peak-dip crossover directly gives
the ratio of the coupling strength of different
leads to the dot, which is a useful information for
the mesoscopic devices.
For the sake of definiteness, let us assume
that for some voltage configuration - see sketch
below - the left lead receives electrons from the
central lead and pumps electrons into the right
lead, the difference of the two contributions
being the total current. For the conductances,
one can write GL=GLC+GLR=GLC − |GLR|. Both GLC
and |GLR| must decay by applying a voltage V - as
the voltage destroys the Kondo resonance and
reduces the electronic tunneling between leads but not necessarily with the same derivative;
then, if dGLC/dV > d|GLR| /dV the conductance
52
GL will increase with V, giving rise to a dip about
V=0. What we specifically mean by
asymmetrically applied bias is shown in the
upper left sketch in the figure below. In one of
the leads, the left one in the given example, the
conductance dI/dV presents a minima at zero
bias, if the asymmetry parameter λ (also defined
in the inset) is greater than a threshold value. As
mentioned, this threshold value is related to the
ration of the couplings of different leads to the
Kondo dot. Using the Keldysh transport
formalism, it can be shown that this limit value is
λ0 = 3 1 + ∆ C / ∆ R .
Fig. 1: Sketch of a quantum dot connected
to three leads, with the bias asymmetrically
applied on the left and right leads
(V and λV, with λ=1/1.4/1.58/1.8/2.5).
(a) The differential conductance through the left
lead changes from peak to dip (around zero bias).
(b,c) Differential conductance through the right
and central lead show a Kondo peak behavior
being maximum in module at V = 0.
The peak-dip crossover, according to our
calculations, is a smooth transition rather than a
Selected Results
sharp one, and in order to find with a greater
accuracy the crossing value for the parameter λ,
we suggest to plot the dip width versus λ, and
find the limit value (where the dip vanishes,
therefore its width goes to zero as well) by
extrapolation, as seen in the graph below.
The first one was the Coulomb pseudogap in the
impurity conduction of doped semicon-ductors
resulting in the T−1/2 dependence of the
hopping conductivity.[3] Then, a zero-bias
anomaly manifested as a dip in the tunneling
DOS was studied in tunnel junctions.[4]
However, what is conspicuous for the three-lead
quantum dots - see again the sketch below- is
that a peak-dip crossover may appear in the
differential conductance while keeping the dot
permanently in the Kondo regime. Our results
were published in [5].
References
Fig. 2: The dip width scaled with temperature, as
function of the asymmetry parameter λ, for three
different temperatures below the Kondo
temperature. The linear temperature dependence
is obvious for λ < 2.4, where the three scaled
curves coincide. The dip vanishes at λ0 = 1.58
which can be obtained by extrapolation.
There are well-known examples of transport
properties influenced by dips in the spectral
function produced by Coulomb interactions.
[1] E. Lebanon and A. Schiller,
Phys. Rev. B 65, 035308 (2001).
[2] R. Leturcq et al,
Phys. Rev. Lett 95, 126603 (2005).
[3] B. I. Shklovskii and A. L. Efros, Electronic
Properties of Doped Semiconductors,
Springer, New York, 1984, p. 228.
[4] B. L. Altshuler and A. G. Aronov, ElectronElectron Interaction in Disordered
Conductors, Elsevier, New York, 1985, p.
46.
[5] M. Tolea, I.V. Dinu, A. Aldea,
Phys. Rev. B 79, 033306 (2009).
53
54
Nano-objects, Thin Films
and Multifunctional Materials
55
Nano-objects, Thin Films and Multifunctional Materials
Selected Results
(001) Bi2Sr2Ca2Cu3O10 Superconducting Thin Films
on Substrates with Large Film-Substrate Lattice Mismatch
and Different Film-Substrate Lattice Mismatch Anisotropy
P. Badica
in cooperation with
K. Endo
Kanazawa Institute of Technology, Japan
Literature indicates that superconducting
c-axis oriented thin films of the phase
Bi2Sr2Ca2Cu3O10 (Bi-2223) were grown by
different methods and on different substrates.
Difficulties encountered in the growth of
epitaxial high-quality single-phase Bi-2223 thin
films were discussed from several points of view
such as: narrow growth window and phase
stability, problems in the precise control of the
stoichiometry (oxygen, cations, and internal
substitutions) and hence of the crystal structure,
specific growth effects that occur when growth is
performed by certain methods (e.g., pulsed-laserdeposition), and the influence of the substrate
through such elements as the type of the
terminal plane and surface or substrate-film
interdiffusion or mismatch. For the last
parameter, growth modes were studied, and in
some cases it was concluded that in-plane
orientation relationships observed experimentally are not explained by the classic near
coincidence site lattice model between
superconducting phase and the substrate.
Presented aspects are pointing toward
complexity of the growth processes as well as on
the insufficient understanding of the growth of
these thin films resulting in poor property
control with severe negative implications on
their use in applications.
On the other hand, high Tc (mean-field
transition temperature around 110 K)
superconducting c-axis, in-plane oriented Bi2223 thin films were prepared by an in situ
sputtering method on (001) SrTiO3 [1]. Metalorganic chemical vapor deposition (MOCVD)
56
on (001) LaA1O3 produced Bi-2223 thin films
considered single-crystal thin films without weak
links because of high critical current density
values, Jc, at 77 K observed up to high magnetic
fields.
If an appropriate substrate is selected,
investigation of Bi-2223 thin films as a potential
candidate for the microwave applications (bandpass filters, resonators, etc.) or as coated
conductors is of high interest.
In this work thin films of (001) Bi-2223
with high zero-resistance critical temperature Tc0
of 75-95.1 K and low roughness up to three
half-c-axis unit cells were grown by metalorganic chemical vapor deposition (MOCVD)
on substrates with large film-substrate lattice
mismatch (from -28.6% to +8.47%) and
different film-substrate mismatch anisotropy.
Fig. 1: Epitaxial relationship between (001) Bi2223 and (a) (001) MgO, (b) (110) MgO, (c)
(001) NdGaO3, and (d) (110) NdGaO3.
Comparative analysis of the (001) Bi-2223
thin films on (001) and (110) MgO and
Selected Results
NdGaO3 (Fig. 1) suggests that Bi-2223 films
can easily accommodate large mismatch filmsubstrate differences, while mismatch on
different directions, that is, mismatch
anisotropy, has a strong influence on the quality
of the film (Fig. 2).
Fig. 4: X-ray diffraction patterns for the Bi-2223
thin films on (a) (001) MgO, (b) (110) MgO, (c)
(001) NdGaO3, and (d) (110) NdGaO3.
Fig. 2: Variation of the zero resistance critical
temperature Tc0 of the Bi-2223 thin films vs. filmsubstrate lattice mismatch anisotropy ratio, r.
Observation in x-ray diffraction (XRD) patterns
of only (00l) lines of the Bi-2223 phase, indicate
that the films are oriented with c-axis
perpendicular to the surface of the substrate.
Atomic force microscopy (AFM) images also
suggest that films are in-plane oriented (Fig. 4).
We conclude that film-substrate lattice
mismatch anisotropy can be used to tune
superconducting properties and surface quality
of the films. Further research is necessary to
understand the mechanism by which stress is
accommodated.
From a practical point of view, our results
and the properties of MgO substrate recommend MOCVD (001) Bi-2223 thin films on
(001) MgO substrate as a suitable candidate for
microwave applications.
Our detailed results are published in Ref. [2].
Fig. 3: AFM images (2 μm × 2 μm) for the thin
films grown on (a) (001) MgO, (b) (110) MgO,
(c) (001) NdGaO3, and (d) (110) NdGaO3.
The highest quality, i.e. low roughness (Fig. 3),
high uniformity, and high Tc0 is obtained when
mismatch anisotropy, taken as the mismatch
ratio (r), is given only by compressive or only by
tensile mismatch stress, and it is around 1. Such
condition is fulfilled for the Bi-2223 thin film
grown on (001) MgO substrate (Fig. 1).
References
[1] L. Miu, P. Wagner, U. Frey, A. Hadish,
D. Miu, H. Adrian, Phys. Rev. B 52,
4553-4558 (1995).
[2] K. Endo, P. Badica, Crystal Growth &
Design, 9 (1), 391-394 (2009).
57
Selected Results
PbI2/polyaniline intercalated material as collector
of charges generated under band to band irradiation
I.Baltog, M. Baibarac
in cooperation with
S.Lefrant
Institut des Materiaux “Jean Rouxel”, Nantes, France
New applications in opto-electronics are
envisaged for hybrid compounds based on the
intercalated layered structures.This family of
solids in which the atoms are arranged
successively in layers, characterized by strong
intralayer chemical bonding and weak
interlayer van der Waals interactions, has
attracted much interest for fundamental
research and technological applications. Among
layered materials, a good example is PbI2, which
has as a rigid structurally repeated unit an I-PbI layer of 0.7 nm thickness arranged
successively and perpendicularly along the c
axis. Intercalation produces an increase in the c
axis parameter as result of the destruction of
stacking continuity of layers along the c axis. In
this sense the Figure1 is illustrative.
and free carriers, are localized. Due to this fact
in the photoluminescence (PL) spectrum at low
temperature (liquid nitrogen temperature –
LNT) of PbI2 at least two emission bands are
detected: one originating from the radiative
recombination of cationic excitons, including
self-trapped excitons, and the other stemming
from the radiative recombination of the trapped
carriers, labeled the G band (~1.96 eV) [1].
Thus, the G band can be considered a measure
of the radiative recombination yield of trapped
carriers produced by band to band irradiation.
In the light of these observations we performed
a systematic study concerning the intercalation
of PbI2 with polyaniline (PANI) as emeraldine
base (PANI-EB) and emeraldine salt (PANIES), which represent an isolator and
semiconducting form, respectively. Such a
product is illustrated below.
+
Fig.1 Experimental illustration of the extending
along the c axis of a PbI2 single crystal by an
intercalation with pyridine
As a general rule, an intercalated structure
exhibits an increased degree of disorder, an
alternation of intercalated and non-intercalated
regions. The “flaky” structure generated in this
way of intercalated PbI2 behaves similarly as the
PbI2 crystalline powder, it being characterized
by a high density of surface defects where the
largest part of the trapping centers (iodine
vacancies, Pb+ ions, dislocations) for excitons
58
PbI2
=
PANI
PbI2/PANI
In general, the PL of a semiconductor
originates in radioactive processes occurring
both at the surface and volume. The weight of
each one depends on the penetration depth of
the exciting light inside the crystal. The
signature of the surface effects becomes
dominant as the energy of the excitation light
increases, i.e., when the exciting light is
absorbed in the surface layers where are
localized the largest density of traps. These
considerations are sustained of the Figs. 2a and
1.8
1.6
2.2
2.4
1.6
1.8
2.2
2.4
1.6
2.2
succesive irradiation
of 6 min at
λexc= 460 nm
cycle 1
cycle 2
cycle 3
cycle 4
2.2
2.0
2.2
2.6
2.4
of 6 min at
λexc= 460 nm
cycle 1
cycle 2
cycle 3
1.8
2.49
2.4
2.48
1.8
2.0
2.6
Excitation wavelength
460 nm
440 nm
420 nm
400 nm
2.0
1.8
c
2.4
2.6
2.6
Energy (eV)
Fig.3 Charges collector effect in PbI2/PANI
compound. PL at LNT of a PbI2 crystalline
micrometric powder (a), PbI2/PANI–EB
compound (b) and PbI2/PANI –ES compound (c).
2.49
a
2.0
2.0
b
2.49
1.6
1.8
of 6 min at
λexc= 460 nm
cycle 1
cycle 2
cycle 3
cycle 4
2.49
1.6
2.0
cycles of 6 min. at
λexc= 460 nm
cycle 1
cycle 2
cycle 3
cycle 4
cycle 5
1.86
Luminescence intensity (arb.units)
b
a
1.8
1.96
2b where one sees that the intensity of G band
progressively increases both with the irradiation
time and the energy of excitation light. The
spectra presented in Fig.2a were obtained after
successive irradiations for 6 minutes at 460 nm;
they illustrate the gradual growth of the
number of trapped electrons and holes which
afterwards by radioactive recombination
generate G band.
2.0
Luminescence intensity (arb.units)
Selected Results
2.6
Energy (eV)
Fig. 2 Photoluminescence at LNT of PbI2 crystalline
micrometric powder at λexc = 460 nm varying the
irradiation time (a) and the energy of excitation
light (b).
The relevant results are those shown in
Fig. 3 where are presented the PL spectra of
a crystalline powder of PbI2 intercalated
mechanico-chemically with PANI in its two
forms, PANI-EB and PANI-ES, respectively.
The inciting fact is the appearance of a weaker
G band when the PbI2 has interacted mechanochemically with PAN-EB and its disappearance
when the interaction has taken place with
PANI-ES.
The explanation is simple. PANI-ES is a
conducting polymer, which interposed
intimately between the PbI2 particles, may play
the role of a charge collector. The intimate term
suggests that a suitable contact between PbI2
particles and the polymer leads to a possible
charge transfer. The mechanism proposed in
this context is that charges formed by band-toband irradiation, before their trapping on the
crystal defects, are immediately collected by
PANI in its conducting form, PANI-ES [2].
References
[1] N.Preda N, L. Mihut, M.Baibarac, I.Baltog,
S. Lefrant, J. Phys. Condens. Mater 18,
8899–8912,(2006)
[2] M. Baibarac, I.Baltog, S.Lefrant, Journal of
Solid State Chemistry182, 827–835, (2009)
59
Selected Results
Synthesis and magnetic properties of Fe-Pt-Nb-B melt spun ribbon
A.D. Crisan, O. Crisan
in cooperation with
I. Skorvanek
Institute of Experimental Physics, Slovak Academy of Sciences, 040-01 Kosice, Slovakia
and
N. Randrianantoandro
LPEC, UMR 6087 CNRS, Université du Maine, 72085 Le Mans, France
60
different annealing procedures were performed,
and the corresponding samples were checked by
X-ray diffraction (XRD) (Fig. 2).
650
60
Tcryst (°C)
70
Heat flow (mW/mg)
In the last years nanocomposite magnets have
attracted considerable attention due to several
technological applications [1]. Nanocomposite
magnets are composed of magnetically hard and
soft phases on a nanometric scale that are
suitably and alternatively disposed within a
homogeneous microstructure and interact via
magnetic exchange coupling mechanisms. The
hard magnetic phase has high anisotropy and
high coercive fields and the soft phase has
enhanced saturation magnetization. Strong
exchange coupling between the hard and soft
phases gives rise to further enhancement in
remanence, coercivity and maximum energy
product. In particular, FePt-based alloys form,
upon appropriate annealing, nanocomposite
spring magnets with high corrosion resistance.
The desired microstructure will consists of
ordered hard magnetic tetragonal L10 FePt phase
with a large magnetocrystalline anisotropy (7x106
MJ/m3) exchange coupled with soft magnetic
cubic A1 FePt. In the alloy, B and Nb were
added. The addition of B allows the formation of
amorphous as-cast state and Nb was added in
order to limit the grain growth during annealing
treatments. The FePtNbB samples were prepared
by melt spinning technique in Ar controlled
atmosphere. The as-cast state is generally
amorphous or nanocrystalline. The crystallization processes are studied using thermal analysis.
Differential scanning calorimetry scans (Fig. 1)
recorded at different heating rates show the
occurrence of a pronounced exothermic peak
that corresponds to the crystallization
temperature (Tcryst). Tcryst increase with the
heating rate (inset of Fig. 1) and rises to around
650°C for a heating rate of 50 K/min. Three
50
640
630
620
0
10
20
30
40
Heating rate (K/min)
50
40
30
10K/min
15K/min
20K/min
20
10
400
500
600
T (°C)
700
800
Fig. 1: DSC scans at various scanning rates
for the Fe57Pt23Nb2B18 ribbons. Inset: evolution
of crystallization temperature with the heating rate.
It can be observed that the spectra of annealed
samples exhibit sharp Bragg peaks, indicating the
high degree of crystallinity in these samples. On
the contrary, the as-cast state was found to be
mainly a mixture of an amorphous state with a
nanocrystalline solid solution of apparently cubic
symmetry, as proven by the indexation of their
Bragg reflections that correspond mainly to the
f.c.c. cubic FePt-rich solid solution. As the
samples are annealed, the microstructure evolves
into refining the width of the Bragg reflections
[2]. This result proves that the incipient
nucleation sites with a cubic symmetry from the
as-cast state, evolve into larger nanocrystals but
keeping the same crystal symmetry. The width of
the Bragg peaks is highly reduced which
indicates the onset of the crystallization process
in the 500/600°C sample, and the decrease of the
Bragg peaks width is more pronounced for the
two samples annealed at 700°C. The main phases
that are indexed in the XRD spectra of annealed
samples are mainly the f.c.t. L10 FePt and f.c.c.
A1 FePt, together with small amount of boride,
formed in later stages of annealing by
polymorphic crystallization of the remaining
amorphous phase [3].
#
* γ1 - FePt (f.c.t.)
# γ - FePt (f.c.c.)
& Fe2B
#
700°C_2h
*
* * * #** * #*** *
* * * #
&
Intensity (a.u)
* *
*
700°C_40'
500°C_1h+600°C_30'
as cast
20
40
60
(2θ)
80
100
120
Fig. 2: XRD spectra of as-cast and annealed
FePtNbB samples. The observed Bragg peaks are
indexed on the figure and corresponds mainly to
L10 FePt (f.c.t.), A1 FePt (f.c.c.) and Fe2B
The magnetic measurements (Fig. 3) were done
at 5K with a superconducting quantum interference device (SQUID), with the applied field up
to 5 Tesla, parallel to the ribbons plane. The
annealed samples show exchange spring behavior
compared to the as-cast sample that is essentially
a soft magnet with high saturation magnetization
and virtually no hysteresis. The annealed samples
show extremely high coercivity values of 14.5
kOe at 5K. After appropriate annealing, an
ordered face-centered-tetragonal (f.c.t.) L10 phase
is formed. X-ray analysis revealed the co-
existence of the soft magnetic body-centeredcubic A1 with hard magnetic f.c.t. L10 FePt
phase and this produces magnetic hardening of
the alloy. In conclusion, the annealed samples
exhibit co-existence of hard and soft magnetic
phases, a two-phase behavior accompanied with
a well-refined grain microstructure. In this way,
we have produced FePt-based exchange spring
magnets with increased energy product (BH)max
[4]. This can be regarded as a novel class of
highly corrosion resistant exchange spring
magnets.
Magnetization (emu/g)
Selected Results
100
as-cast
700C_40'
700C_2h
50
0
-50
Field //
5K
-100
-60000 -40000 -20000
0
20000 40000 60000
Field (Oe)
Fig. 3: Hysteresis loops at 5K recorded for as-cast
and annealed FePtNbB samples in parallel applied
field
References
[1] X. Ruj, E Shield, Z. Sun, Y. Xu, and D.J.
Sellmyer, Appl. Phys. Lett. 89, 122509
(2006)
[2] A.D. Crisan, O. Crisan, I. Skorvanek, N.
Randrianantoandro, J. Optoelectron. Adv.
Mater. 10, 786 (2008).
[3] A.D. Crisan, J. Optoelectron. Adv. Mater.
(2009) accepted for publication
[4] N. Randrianantoandro, A.D. Crisan, O.
Crisan, I. Skorvanek, J. Kovac, J. Appl. Phys.
(2009) submitted
61
Selected Results
Mechanochemical Synthesis and Sensing Properties of Zirconium-Doped
Hematite Nanoparticles
L. Diamandescu, A. Tomescu
in cooperation with
M. Sorescu, S. Krupa
Duquesne University, Department of Physics, Pittsburgh, PA, U.S.A
xZrO2.(1-x)Fe2O3 , x=0.1;

e

α-Fe2O3
12 h
• ZrO2 monocl.

d




I n t e n s i t y ( a. u. )
Investigations of semiconducting oxides have
become increasingly important due to their
sensing properties in the detection of toxic gases,
such as carbon monoxide or methane [1]. With
the aim to investigate the gas sensing properties
of the nanoparticles system xZrO2-(1-x)α-Fe2O3
(x=0.1) we applied the mechanochemical route
of synthesis. Powders of hematite and zirconium
dioxide (corresponding to x=0.1) were milled in
the SPEX 8000 mixer mill for time periods
ranging from 0 to 12 hours. The ball/powder
mass ratio was 5:1 and all experiments were
performed in a glove box under protective argon
atmosphere. The structure of the powders, was
investigated by means of X-ray diffraction
(XRD) (Figure 1). Rietveld refinements [2]
reveal a progresive substitution of iron by
zirconium ions, as well as a drop in particle size
down to 9 nm as the ball milling time increases
up to 12 hours. Gas sensing measurements were
performend in the presence of CO and CH4.
Figure 2 shows the determination of the optimal
temperature from the point of view of the
sensitivity and stability of the zero resistance for
the system xZrO2-(1-x)α-Fe2O3 (x=0.1, ball
milling time of 12 hours).





8h

•





c


• •

b

4h





2h

• •





a
0h

• •
20
30

40




50
60
70
2θ (deg)
Fig. 1: XRD patterns of zirconia-doped hematite
for x=0.1 and milling times (a)-(e) of 0-12 hours,
respectively.
Fig. 2: The resistance as function of time for the
xZrO2(1-x)α-Fe2O3 system for x=0.1 and ball
milling time of 12 hours, for CO and CH4 gases at
four different temperatures, RH=0.
62
Selected Results
The test was performed at four temperatures and
high concentrations: 1000 ppm CO and 5000
ppm CH4. It can be seen that the zero
resistance, sensitivity (S=Rair/Rgas), response time
and recover time are all functions of temperature.
Given that all these parameters are of interest, we
selected the temperature of 350 oC for further
investigations. At this temperature we tested the
response of the oxide system to CO over a range
of concentrations between 50 and 1000 ppm. It
may be observed in Figure 3 that the material is
sensitive to CO over the entire set of
concentration values and that the sensor signal
tends to saturate at high CO concentrations
(250-1000 ppm).
We further checked (Figure 4) the linearity
of the signal as function of CO concentration
(25-250 ppm) in the presence of air with variable
humidity (0.30 and 50 % relative humidity,
RH).
Fig. 3: The sensor signal as a function of CO
concentration for the xZrO2(1-x)α-Fe2O3 system for
x=0.1 and ball milling time of 12 hours.
Fig. 4: The sensor signal as function of CO
concentration at 350 oC and relative humidity
RH=0.30 % and 50 %, for the xZrO2(1-x)αFe2O3 system at x=0.1 and ball milling time of 12
hours.
We could conclude that the material is
sensitive over the entire range of CO concentrations and moreover, the sensor signal depends
linearly on the CO concentration, result which
demonstrates the outstanding potential of this
system for sensing applications. The relative
humidity of air influences slightly the reference
value of the electrical resistance and the slope of
the signal, but does not affect its linearity.
Around the detection limit for CO (30-50 ppm)
the signal is practically not affected by the
variation of the air humidity and this aspect is
very important for field applications.
References
[1] J. Tamaki, C. Naruo, Y. Yamamoto,
M. Matsuoka, Sens. Actuators B 83, 190
(2002).
[2] M. Sorescu, L. Diamandescu, A. Tomescu,
S. Krupa, Physica B 404, 2159 (2009).
63
Selected Results
Optical properties of dye doped potassium hydrogen phthalate (KAP) crystals
and nanorods
M. Enculescu
in cooperation with
C. Trautman, and R. Neumann
GSI, Planckstr. 1, D-64291, Darmstadt, Germany.
Fig. 1. C6 doped KAP crystals grown from aqueous
solution.
Fig. 1 presents coumarin 6 (C6) doped KAP
crystals [1]. Under excitation with 350 nm, C6
doped KAP shows a luminescence emission band
peaking at 450 nm (Fig. 2). When the excitation
wavelength is doubled (670 nm, 700 nm or 730
nm), a sharp band peaking at half of the
excitation wavelength (335 nm, 350 nm or 365
nm) is obtained beside the dye emission band
peaking at 450 nm, proving the second
harmonic generating properties of the crystals
(Fig. 3).
64
Intensity (a.u.)
100
50
0
300
350
400 450 500
Wavelength (nm)
550
600
Fig. 2. The spectra of C6 doped KAP crystal:
emission excited with 350 nm (solid), emission
excited with 700 nm (dashed) and excitation for
the 450 nm emission (dotted).
Emission intensity (counts/105)
Studies regarding dye-doped solid-state lasing
materials are mainly aimed on polymers, clays or
liquid crystals. An easily growing non-linear
optical (NLO) single-crystalline material that
combines the qualities of liquid dye-lasers (high
efficiency and broadband tuneability) with the
flexibility and the convenience in operation
offered by a crystalline material it is a very
interesting alternative. Potassium hydrogen
phthalate or potassium acid phthalate (KAP) is a
material very soluble in water that crystallizes in
normal conditions and plays an important role in
the field of non linear optical materials. Recent
studies present the importance of the
luminescence and up conversion due to second
harmonic generating properties of KAP crystals
doped with different dyes [1-3].
12
10
8
6
4
2
0
300
400
500
Wavelength (nm)
600
Fig. 3. C6 doped KAP emission spectra excited with
670 nm (dashed) 700 nm (solid) and 730 nm
(dotted).
As-grown rhodamine 6G (Rh 6G) doped KAP
crystals are presented in Fig. 4. Rh 6G doping of
the KAP crystals in a concentration of 10-5 M
results in a fairly uniform pink coloration (Fig.
4a). Usually, high concentration of dye in the
growth solution leads to the dye segregation. In
this case, islands of high dye concentration can
be observed (Fig. 4b). Using undersaturated
solutions we obtained uniformly Rh 6G doped
KAP crystals with 5x10-5 M and 10-4 M dye
Selected Results
concentration in solution, as presented in Figs. 4
c and 4 d.
a
b
c
d
Fig. 4. Rh 6G doped KAP crystals with different
dye concentrations: a). 10-5 M, b). 2.5x10-5 M, c).
5x10-5 M and d). 10-4 M
increasing of Rh 6G concentration in the
aqueous solutions used for crystal growth.
We applied solution growth to fabricate
micro and nanorods of Rh 6G doped KAP [4].
PC foils 100 and 30 μm thick were irradiated
with swift heavy ions with the specific energy of
11.4 MeV/nucleon and fluences in the range 105
– 109 ions/cm2 at the UNILAC linear accelerator
(GSI). The ion tracks were etched using an
aqueous solution of 6 M NAOH at 50°C. The
membranes were placed on the surface of the
growth solution and left to float [5]. Under 480
nm excitation, the PC membranes containing
nanorods (100 nm diameter) exhibit intense
luminescence bands peaking at 581 nm (Fig. 6).
When compared with the micrometrical sized
rods or the bulk crystals emission bands, a red
shift is observed due to the increased
concentration of the dye.
The luminescent properties of Rh 6G doped
KAP were investigated [3] (Fig. 5).
Emission Intensity (a.u.)
6
2x10
Emission intensity (counts)
1200
1x106
900
600
300
0
500
0
500
100 nm rods
5 µm rods
bulk crystal
550
600
650
700
750
Wavelength (nm)
550
600
650
700
Wavelength (nm)
Fig. 5. Emission spectra of Rh 6G doped KAP
crystals with different dye concentrations: 10-5 M
(triangles), 5x10-5 M (circles) and 10-4 M (squares).
The intensity of the luminescence is high and the
photostability is noticeable. Rh 6G doped KAP
crystals have wide emission bands excited with
480 nm wavelength. For the lowest dye
concentration (10-5 M) the emission spectrum
presents only one emission band peaking at 560
nm. As expected for the higher dye
concentrations, a band peaking at shorter
wavelength (540 nm) appears. The intensities of
the emission bands are increasing with the
Fig. 6. Emission spectra of Rh-6G doped KAP
excited at 480 nm: bulk crystal (squares), 5 µm
diameter rods (triangles) and 100 nm diameter rods
(circles).
References
[1] M. Enculescu, Opt. Mater. 32 (2009) 281
[2] J.R. Benedict, P.M. Wallace, P.J. Reid, S.H.
Jang, B. Kahr, Adv. Mater., 15 (13) (2003)
1068
[3] M. Enculescu, E. Matei, N. Preda, I.
Enculescu, Optoelectron. and Adv. Mat.Rapid Comm. 3 (11) (2009) 1210
[4] M. Enculescu, C. Trautmann, Rad. Meas.
doi:10.1016/j.radmeas.2009.11.015
[5] M. Enculescu, J. Optoelectron. Adv. Mat.,
10/6 (2008) 1501
65
Selected Results
Dielectric properties of paraelectric Ba1-xSrxTiO3 ceramics
A. Ioachim, L. Nedelcu, M.I. Toacsan, M.G. Banciu, P. Ganea
in cooperation with
H.V. Alexandru, C. Berbecaru
University of Bucharest, Faculty of Physics
Ferroelectrics are very attractive for microwave applications due to the nonlinear variation
of their permittivity with the applied electric
field. In this type of applications, materials are in
the paraelectric phase in order to avoid high
dielectric loss and thermal hysteresis. Specific
applications require tailored Ba1-xSrxTiO3
materials [1] with the Sr content x higher than
0.4 in order to obtain a transition at a temperature close to, but less than the room temperature.
Ba1-xSrxTiO3 ferroelectric materials (BST)
were prepared by solid-state reaction at
1260 oC/2h. BST 40, BST 50, BST 60 and
BST 75 samples correspond to x = 0.4, 0.50, 0.6,
0.75, respectively. The dispersion of the complex
dielectric constant εr = ε` - i ε`` was investigated
in the large frequency range [2]
For BST 40 sample the temperature
dependence of the complex dielectric constant is
given in Fig. 1. It can be seen that the sample is
in paraelectric state at room temperature and
exibits a maximun value of ε` at Curie
temperature Tc = 0 oC.
behaviour of ε`, but the slope of curve ε`(f)
decreases with the distance to the Curie point.
The different values of ε` are due to the
strontium contribution, which depresses the
transition temperature and reduces the
polarizability of Ba1-xSrxTiO3 samples.
Fig. 2: Real part of complex dielectric contant ε`
versus frequency for BST samples
The dielectric constant ε` and loss
(tanδ = ε``/ε`) measured in microwave domain
at room temperature are presented in Fig. 3. It
can be seen that the dielectric constant decreases
with the increase of Sr content for all Ba1xSrxTiO3 samples. At the same time, the dielectric
loss decreases with the increase of Sr content.
Fig. 1: Complex dielectric constant versus
temperature for BST 40 sample
The frequency dependence of the real part of
the complex dielectric constant measured at
room temperature for BST samples is shown in
Fig. 2. All BST samples exhibit the same
66
Fig. 3: Dielectric constant and loss versus strontium
content for Ba1-xSrxTiO3 samples
sintered at 1260 oC/2h
Selected Results
Taking into account de above results, a
special emphasis was put on compositions with
x = 0.4. Four sintering temperatures Ts (1300,
1350, 1400, 1450 oC) were used in order to
investigate the influence of the microstructure on
the dielectric properties of the materials. The Xray diffraction patterns of the BST 40 sintered
pellets showed that the Ba0.6Sr0.4TiO3 is the
major phase, but there is a small amount of
secondary phases.
The increase of Ts induces changes in the
grain morphology. While at 1300 oC (Fig.4a),
the grains have a polyhedral shape with wellformed edges and corners, at 1350 oC curved
surfaces for the large grains appear, at 1400 oC,
the corners and edges are rounded and, finally, at
1450 oC (Fig. 4b) BST 40 presents large
spherical grains.
Ts = 1400 oC for BST 40 materials. In the
temperature range 1300 - 1450 oC, the dielectric
loss tangent varies non-monotonically between
0.77 % and 0.96 %. The lowest value of the loss
tangent was achieved for BST 40 samples
sintered at 1400 oC for 3h. Therefore, the
sintering temperature Ts = 1400 oC is the most
appropriate for simultaneously achieving the
highest dielectric constant and the lowest
dielectric loss in the microwave range.
Dielectric measurements at low frequency (1
kHz) have been performed with the self-acting
RLC bridge HIOKI 3522-50. The temperature
dependence of the dielectric constant ε` of
BST 40 samples at 1 kHz is shown in Fig. 6. All
samples exhibit narrow transitions from the
ferroelectric to paraelectric state.
a)
b)
Fig. 4: SEM images of BST 40 samples for
Ts = 1300 oC/3h (a) and Ts = 1450 oC/3h (b)
The microwave dielectric parameters of the
BST 40 samples measured at room temperature
are presented in Fig. 5.
Fig. 6: Temperature dependence of the dielectric
constant for BST 40 samples for different sintering
temperature.
High values of ε` and moderate dielectric loss
were achieved in microwave range. These
features make the paraelectric Ba1-xSrxTiO3
ceramics attractive for high frequency
applications. When a material is targeted for a
specific application, the optimum Sr content is a
compromise between the high ε` and low tanδ.
Fig. 5: Dielectric constant and loss versus sintering
temperature for BST 40 samples.
As the sintering temperature Ts increases,
there is an increase in the dielectric constant,
followed by a slight decrease. The microwave
dielectric constant reaches its maximum at
References
[1] C. Berbecaru, H.V. Alexandru,
C. Porosnicu, A. Velea, A. Ioachim,
L. Nedelcu, M. Toacsan, Thin Solid Films
516, 8210 (2008)
[2] L. Nedelcu, M.I. Toacsan, M.G. Banciu,
A. Ioachim, Ferroelectrics 391, 33 (2009)
67
Selected Results
Studies on bare and thiolate covered GaAs (hkl) surfaces
M.F.Lazarescu
in cooperation with
V.Lazarescu, R.Scurtu
Institute of Physical Chemistry, Bucharest, Romania
A.M.Toader, E. Volanschi
Dept. of Physical Chemistry, University of Bucharest, Romania
and
E.Santos,H.Jones, G.Gotz, P.Bauerle
University of Ulm, Germany
Surface phenomena such as potential-induced
effects on the adsorption geometry of α-CNterthiophene thiolate (CNTS)/n-GaAs (110)
substrates, and surface states effects at p and ndoped GaAs(111)A / solution interface have
been studied by SHG (optical Second Harmonic
Generation), EIS (Electrochemical Impedance
Sectroscopy) and XPS (X-Ray Photoelectron
Spectroscopy) measurements.
SHG and EIS investigations on α-CNterthiophene-thiolate
covered
GaAs(110)
electrodes in 1 N H2SO4 solution revealed
significant changes in the rotational anisotropy
of the SH response around -250 mV/SCE due to
the charging of an important group of surface
states located about 1.06 eV below the
conduction band edge. Such surface states are
supposed to correspond to the lowest
unoccupied molecular orbital of the organic
molecule with εLUMO = -1.707 eV estimated by
semiempirical MO calculations as the most
favorable for an electronic interaction with the
semiconductor substrate.
XPS data analysis. Figure 1 displays the XPS
data for the S 2s, and N 1s regions of the CNTSmodified GaAs electrodes before (top) and after
the application of the potential scan (bottom). In
both cases, the samples were stored in air over
several days before XPS measurements were
made. All spectra were analyzed by applying
curve fitting with Gaussian line shapes and
comparing the peak positions to literature data.
The presence of sulfur in the CNTS
adsorbed layer was monitored in the S 2s core68
level region because the S 2p core line is partially
overlapped by the Ga 3s contribution. The
significant shift of the thertiophene-S BE clearly
indicates that sulfur atoms chemically
Fig. 1: XPS spectra of CNTS / GaAs(110)
interact with the GaAs substrate, resulting in a
stable compound. The three thertiophene-S
atoms obviously experience a different electronic
environment that should result only from a
change in the molecular configuration bringing
the terthiophene rings closer to the surface. This
assumption is further supported by the new N 1s
species revealed in the XPS spectra recorded for
the electrochemically biased CNTS-GaAs
electrodes.
Selected Results
Investigations on the potential dependence
of the SH response generated at GaAs(111)A
electrodes/solution interface, revealed that a
significant part of the observed signal comes
from the surface region, where the second-order
polarizability is enhanced by the electric field.
However, while n-doped GaAs(111)A exhibits a
remarkable stability over a relatively large potential range, p-GaAs(111)A seems to be much
more reactive. The potential dependence of the
SHG response (Fig.2) was found to be closely
(a)
(b)
Fig.2: SH-isotropic parameter/potential
for n-GaAs(111)A (a) and p-GaAs(111)A (b)
related to the changes in the surface state
population.. The sensitivity of the SH signal to
the applied potential shows that a large part of
the signal originates at the interface and is
dominated by the electric field-induced second
harmonic (EFISH) response from the
semiconductor space charge layer. Surface states
are present at GaAs(111)A/H2SO4 interface and
they play an important role in the local charge
redistribution which affects the field gradient
operating in the interfacial region
The dopant type (Te/Zn) does not influence the
location of the surface/interface states within the
band gap but enhances their densities for both
the deep (Ec-0.8 eV) and the shallow (Ec-1.1
eV) levels and increases their filling/emptying
rate constants. The higher instability of the pGaAs(111)A surface may be therefore tentatively
assigned to these changes in the surface states
attributes.
References
[1] V.Lazarescu, R.Scurtu, M.F.Lazarescu,
A.M.Toader, E.Volanschi E.Santos, H.Jones,
G.Goetz, P.Bauerle, Langmuir 25(11)
(2009), pp 6522–6531
[2] R. Scurtu, N. Ionescu, M. Lăzărescu,V.
Lăzărescu, Phys.Chem. Chem.Phys., 11
(2009), pp. 1765–1770
69
Selected Results
The magic glass
M. Popescu, A. L őrinczi, F. Sava, A. Velea
National Institute of Materials Physics
105 bis Atomistilor Str., 077125 Bucharest-Măgurele, Romania
70
attached to the end of optical fibers determines
the focusing of the laser radiation guided
through the optical fiber. This feature is used in
laser-ophtalmology and laser surgery (see Fig. 1a)
[2, 3].
a
b
Fig. 1. Microlenses mounted on optical fibers (a)
and a bunch of such optical fibers (b).
A network of microlenses improves the
homogeneity of the laser beam in the
optoelectronic circuits (see Fig. 1 b).
By appropriate techniques we have produced
photonic lattices wich give rise to forbidden
energy bands as the light passes through these
structures, the so-called photonic crystals (see Fig.
2 a, b) [4].
0.92
Frecvency
Glasses belong to the disordered state of the solid
matter. Around us are glasses: windows,
packages, windshields, eye-glasses, etc.
Among the glasses there is a special class, the
chalcogenide glasses. These glasses are binary and
ternary combinations with chemical elements
called chalcogens: sulphur, selenium and
tellurium.
The chalcogenide glasses have drawn the
attention of the researchers by their properties
which opened the way for applications in optics,
electronics, opto-electronics and information
technology.
As an example is the As2S3 compound. In the
crystalline state it has red colour, it is transparent
for red and infrared (IR) light, and does not
change its colour and transparency during
illumination. On the contrary, As2S3 glass
subjected to irradiation with light of different
wavelengths will change the colour and the
transparency as a function of the particular
wavelength and intensity. Moreover, the glass
changes even its volume and exhibits
optomechanical effect, which consists in the
reversible volume expansion upon irradiation.
This phenomenon is applied in atomic-force
microscopy (AFM).
Other effects are the photo-darkening (PD)
and the photo-bleaching (PB) under the effect of
a light irradiation with wavelength close to values
correspondig to the forbiddeen gap’s width.
These effects are used in the warning systems,
protection and detection systems of IR sources,
like night vision and other survailence purposes.
In our Institute we conduct researches with
emphasis on chalcogenides with As2S3 and Asselenides. We have developed a procedure to
produce chalcogenide-glass microlenses (Patent
No. 6/146/30.11.2009) [1]. These microlenses
0.90
0.88
6.0
100 μm
a
6.2
b
ε
6.4
Fig. 2. Optical micrograph of a 2D photonic
structure (a), and the forbidden photonic gap (b).
Upper limit of the gap is marked with green, and
the lower limit with red colour.
Chalcogenide compositions which exhibit
phase-change effect have been prepared by using
pulsed laser deposition (PLD) technique. The
memory chalcogenide glasse changes its
resistivity from the conductive state to the
insulating state under the influence of an
Selected Results
electrical signal. The phenomenon is reversible
and is essential to to get smart memories for the
future computers [5].
An elementary demonstrative memory cell
with 10 cells has been developed and patented
(Patent Request in 2008) [6].
Recently, new features of the glasses and thin
amorphous films have been observed in compositions based on amorphous chalcogenides. We
had the idea to deposit the chalcogenide material
by evaporation through a screen mounted
between the source and the deposition substrate.
The results are surprising and new morphologies
of the deposited material has been observed, like
dendrites, fractals and other exotic morfologies
(see Fig. 3 a-c).
Our measurements indicated an advancement of the diffusion front with a velocity of
vd = 6.84 mm/h [10].
Fig. 4. The evolution of the Ag / As2S3
heterostructure’s surface morphology upon different
irradiation times (0, 40, 50, 60, 210 and 1110
seconds).
References
Fig. 3. Optical micrograph of various 2D
morphologies: fractals (a), den-drites (b) and rodlike structures (c).
When the As-chalcogenide is deposi-ted on a
Ag film with nanometric thickness, it is observed
the diffusion of Ag in the glass during the
illumination of the hetero-structure. Fig. 4 shows
the diffusion state at different moments [7].
The chalcogenide becomes deeply modified
by the diffused silver [8]. The chalcogenide
changes deeply its colour and surface
morphology. Inflation points appear the colour
turns from light red to dark red, and dendritic
surface formations can be observed. The
formation of round spots under irradiation is
illustrated in Fig. 4 [9].
[1] Patent OSIM 6/146/30.11.2009
[2] Rusu M, Velea A, Popescu M
J. Optoelectron. Adv. Mater. 10 (12), pp.
3169-3171 (2008)
[3] Velea A, Rusu, M, Popescu M,
J. Optoelectron. Adv.Mater. 11(10), pp.
1379-1383, (2009)
[4] Popescu M et al., J. Optoelectron. Adv.
Mater. 7(2), pp. 1103-1106 (2005)
[5] Popescu A et al, J. Optoelectron. Adv.
Mater. 11(11), pag. 1874 – 1880 (2009).
[6] Popescu M et al., Optoelectron. Adv. Mat.Rapid Comm. 3 (9) pp 851-859 (2009)
[7] Popescu M, Nezzane D, Optoelectron.
Adv. Mat.-Rapid Comm. 2 (1) pp 2628 (2008)
[8] Popescu M et al,
Patent req. OSIM no A 2008 /00724/
2008.
[9] Le verre magique, Bulletine Electronique de
l’Ambassade de France en Roumanie,
Decembre 2009.
[10] Popescu M et al, J. Optoelectron. Adv.
Mater. 11(11), pag. 1586 – 1594 (2009).
71
Selected Results
Structural investigations on Cathode/Electrolyte systems for IT-SOFCs
N. Popescu - Pogrion, I.Mercioniu, A. Ionascu , S. Constantinescu
in cooperation with
C. Ghitulica, B.S. Vasile, E. Andronescu
Applied Chemistry and Materials Science Faculty, University POLITEHNICA Bucharest
A. Popescu, G. Dorcioman, I. Mihailescu
LSPI Department, National Institute for Laser, Plasma and Radiation Physics
J .Tartaj
Electroceramics Department, Instituto de Cerámica y Vidrio (CSIC), Madrid, Spain
72
electron microscopy (HRTEM), in correlation
with statistical measurements [3].
XRD spectrum has been obtained using a
Bruker D8 Advance diffractometer with CuKα
source cathode. One evidences the diffraction
lines of LSFC rhombohedral phase [ASTM 00049-0284], with unit cells parameters slightly
modified a=b=5.476A; c=13.390A and the
diffraction lines of CeO2 cubic phase, [ASTM:
03-065-5923] with a(Ce-Y) = 5.392Ǻ also
slightly modified relative to a (CeO2) = 5.404Ǻ,
probably due to the presence of yttria in the ceria
structure.
[111]*
1.00
0.75
I(2θ)exp/Io [u.a.]
Yttrium doped cerium dioxide is a fluoritestructure oxide into which many oxygen
vacancies are introduced by substituting Y+3 for
Ce+4. Fine Ce-Y oxide powders were prepared by
coprecipitation followed by calcinations at
500°C. To obtain Ce-Y nanopowders, crystals of
Ce (NO3)36H2O, were used together with Y2O3
nanopowders, distilled water and NH4NO3. The
final co-precipitate product was calcined 2h at
500°C
obtaining
10mol%Y2O3
doped
CeO2:(10YCe)
nanopowders
[1].
The
nanopowders were isostatic pressed at 200 MPa
obtaining the 10YCe green bodies. The resulted
green bodies were sintered at 15000C for 5h
obtaining the sintered compacts.
Perovskites La0.6Sr0.4Fe0.8Co0.2O3-δ (LSFC) are
chosen as cathodes [2]. The choice of an
appropriate thin film deposition technique is
strongly influenced by the material to be
deposited and the desired film quality. Pulsed
laser deposition (PLD) is a physical method of
thin film deposition in which a pulsed laser beam
is employed to ablate a target composed of the
desired film material, which is subsequently
deposited onto the Ce-Y electrolyte substrate.
The PLD experiments were performed, using a
KrF excimer laser source ((λ=248 nm, τ=25 ns),
the laser energy 450 mJ, the laser fluence
(energy/surface) was set at 3J/cm2, support
temperature 200 0C.
The structure of the resulting cathode/
electrolyte system specimens were investigated by
X-ray diffraction (XRD), transmission electron
microscopy (TEM, SAED) and high resolution
0.50
+
[012]
20
[311]*
[202]+
[006]+
0.25
0.00
[220]*
[200]*
[104]+
[110]+
[222]* [400] [331]
[024]+ [220]+
[420]
[208]+
[024]+
30
40
50
60
70
80
2θ [grd]
Fig. 1 The indexed XRD spectrum of the PLD
deposed LSFC(La.6Sr.4Co.2Fe.8O3-δ) on Ce-Y
(sintered body)
Conventional
transmission
electron
microscopy (TEM) was performed on a JEOL
200CX electron microscope and high resolution
transmission electron microscopy (HRTEM) on
a TecnaiTM G2 F30 instrument. Cross section
Selected Results
samples of the cathode/electrolyte (LSFC/Ce-Y)
system were prepared by focuses ion beam (FIB)
method with a FIB- SEM type Lyra I (Fig. 2).
Electrolyte
2.74 (110) LSFC
Interface
Cathode
Fig 2 TEM on cathode/electrolyte system
prepared by FIB
The HRTEM investigations on cross section
samples (Figs.3, 4) evidence the following aspects
for cathode (a) / electrolyte (b):
(a) cathode: •the film is crystalline; •the thick
of the layer is between (0.5 – 2.25) µm and
isn’t uniform; •the shape of the grains is
polyhedral; •the mean grain size is (0.85 ±
0.10) nm and was statistically determined;
•the shape of pores is spherical; •the mean
pore size is (0.2 ± 0.09) µm;
(b) electrolyte: the ceramic is crystalline; •the
shape of grains is polyhedral; •the mean
grains size is (1.24± 0.042) µm and was
statistically determined; •the porosity is 2%;
the mean pore size is (0.27 ± 0.078) µm. [4].
Fig. 3 HRTEM images of the cathode film (LSFC)
[(110) planes]
1.95 (220)
2.7 (200)
Fig. 4 HRTEM images of the electrolyte support
exhibiting (200) and (220) planes
References
[1] A. Moure, J. Tartaj, C. Moure, J. Am.
Ceram. Soc., 92 [10] 2197–2203 (2009)
[2] D. Beckel et al, J. Power Sources 173 (2007)
325 – 345
[3] B. Vasile et al, JOAM, 9, [12], 3774 – 3780
(2007)
[4] N. Popescu – Pogrion et al, J. Am. Ceram.
Soc., in press.
73
Selected Results
Photoluminescence and thermoluminescence of ZnO nano-needles and arrays
C.E. Secu, Mariana Sima, M. Sima and M. Secu
Fig. 1: SEM images of Zn foil anodized at a
constant current density of 0.3mA/cm2 in potassium
zincate solution for 80 min.
ZnO nano-needle arrays and films have been
prepared by anodic etching of ZnO foil at
constant current in potassium zincate solution
and sodium hydroxide alcoholic solution,
respectively [2].Scanning electron microscopy
(SEM) images have shown ZnO nano-needles of
≅100nm length (Fig.1) and ≅10nm diameter.
On the other hand, a relatively smooth, uniform
ZnO film was developed during anodic etching
in an alcohol solution containing sodium
hydroxide (Fig.2).
As the ZnO particles become smaller, ions at
the surface increase rapidly and most ions at the
surface are not saturated in coordination [1]. The
charge carriers, electrons or holes, are easily
excited and may escape from these ions; they are
subsequently trapped at defects associated with
surface states located in the forbidden gap.
During heating, the charge carriers are thermally
released and yield TL [1,3].
Thermoluminescence (arb.units)
The optical, electrical and piezo-electrical
properties of zinc oxide are widely used in
various applications as photoanode in high
efficiency dye-sensitized solar cells, light-emitting
diodes, lasers, field-emission devices and
chemical sensors. The control of the defects in
ZnO films, nanowires or nanodots is a necessary
step in order to improve the quality of these
devices. Charge carriers trapped at the surface
states or defects sites are released by heating
giving thermoluminescence (TL); traps and
carriers are produced during the samples
processing [1].
200
150
ZnO nano-needles
ZnO film-type
ZnO polycrystalline powder
100
50
0
50
100 150 200 250 300 350 400
Temperature (oC)
Fig. 3: Thermoluminescence curve recorded on
ZnO nano-needles anodized in potassium zincate
solution and alcohol solution and ZnO powder
(heating rate β=2oC/sec).
Fig. 2: SEM images of Zn film anodized
at a constant current density of 0.05mA/cm2
in alcohol solution.
74
TL curves of ZnO nano-needles have shown
a broad and composite peak at about 360oC (Fig.
3) which was attributed to the recombination of
the trapped carriers which are produced during
the sample processing.
Selected Results
Photoluminescence (arb.units)
The TL curves recorded on ZnO nanoneedles and polycrystalline powder are quite
similar (Fig. 3) suggesting a linkage of the defects
and TL mechanism; the broad shapes of the TL
peaks indicates a distribution of traps. Oxygen
related defects sites as singly occupied oxygen
vacancies (isolated, or associated with other
impurities or defect sites) or vacancy-interstitial
pairs have been observed in ZnO polycrystalline
powders [4] similar to those observed in ZnO
nanowires. The TL curve of ZnO film-type
sample shows a distinct and very strong TL peak
at about 325oC superimposed on a broad one
(Fig. 3). The sharp TL peak might be associated
with the well defined trap sites; their nature is
however unknown.
The nature of the traps was revealed by the
photoluminescence (PL) which largely depends
on the synthesis method, the nano-crystallites
size, and most importantly the defect concentration in the bulk and on the surface [5].
300
250
ZnO nano-needles
ZnO film-type
ZnO powder
200
150
100
50
0
350 400 450 500 550 600 650 700 750 800
Wavelength (nm)
Fig. 4: Photoluminescence spectra recorded on ZnO
nano-needles anodized in potassium zincate
solution, in alcohol solution and in ZnO
polycrystalline powder (λex.=345nm).
We noticed in all the ZnO samples a small
band at about 375nm which is due to excitonic
luminescence of ZnO. Since in the case of ZnO
nano-needles the PL spectra have shown a broad
PL band at about 585nm (Fig. 4) which is
related to the interstitial oxygen ion centres[6]
we suppose that TL is mainly due to the
recombination of charge carriers released from
the surface states associated with these centres.
The PL spectra recorded on polycrystalline ZnO
(Fig. 4) have shown a dominant band at 510nm
which was attributed to recombination of the
singly occupied oxygen vacancies [6]. Therefore
we suppose that in this case TL is mainly due to
the recombination of charge carriers released
from the surface states associated to the singly
occupied oxygen vacancies centres.
Additional support for the TL mechanism in
the ZnO nano-needles samples is given by the
recovery effect of the PL and TL. We noticed
that both completely vanish in all the samples
after annealing at 400oC, i.e. after the TL
measurements. However after about two months
of storage in an open atmosphere, about half of
the PL signal is recovered and the TL signal was
about two times larger This observation supports
the assumption that both PL and TL are due to
surface states related to the interstitial oxygen ion
centres.
Together with other techniques, TL is a very
useful tool to extract information about the
surface states of nano-particles.
References
[1] Wei Chen, Zhanguo Wang, Zhaojun Lin,
Lanying Lin J. Appl. Phys. 82, 3111 (1997).
[2] Mariana Sima, E.Vasile, M. Sima, T.Visan,
Analele Univ. Oradea (Chimie), Vol XV, 98
(2008).
[2] C. E. Secu and Mariana Sima, Optical
Materials 31, 876 (2009).
[4] K. Vanheusden, W. L. Warren, C. H. Seager,
D. R. Tallant, J.A. Voight and B.E. Gnade,
J. Appl. Phys. 79, 7983 (1996).
[5] Gang Xiong, U. Pal and J. Garcia Serano,
J. Appl. Phys. 101, 024317 (2007).
[6] X.L. Wu, G.G. Siu, C.L. Fu, H.C. Ong,
Appl. Phys. Lett. 78, 2285 (2001).
75
Selected Results
Synthesis, mechanism and gas sensing applications
of surfactants tailored tungsten oxide nanostructures
C. E. Simion, V. S. Teodorescu,
in cooperation with
S. Pokhrel, N. Bârsan, U. Weimar
Institute of Physical Chemistry, Auf der Morgenstelle 15, Tübingen University,
72076 Tübingen, Germany
A series of various morphological (rods,
plates and porous) nanoparticles of WO3 can be
developed using a halide precursor in presence of
surfactants such as DFOM, CTAB and Pluronic
P123 [1].
The tungsten oxide nanomaterials and
reaction solutions have been characterized by
FT-IR, 1H and 13C NMR, XRD, SEM, TEM,
HRTEM and SAED. The indexing of the line
pattern suggests WO3 is in monoclinic structure
with: a = 0.7297 nm, b = 0.7539 nm, c =
0.7688 nm, β = 90.91°. The nanoparticles found
in various architectures such as chromosomal
(material I), slates (material II) are quite different
from the mesoporous one (material III) having
internal pores or mesopores pores ranging from 5
to 15 nm. The nanoparticles obtained from all
the synthetic procedures were in the range of 4060 nm.
The investigation of the gas sensing
properties of these materials indicate that all the
sensors have good baseline stability and the
sensors fabricated from material (III) present
very different response kinetics and different CO
detection properties [2]. The TEM images of the
annealed samples provide insight into the
structure of the WO3 crystallized nanoparticles.
The selected area electron diffraction (SAED)
pattern depicted in Figure 1(a) shows the
monoclinic structure of the sample (I); all the
samples show practically an identical SAED
pattern [3]. The line indexing of the SAED
pattern was identical with the monoclinic
structure of WO3 (JCPDS card No. 43-1035).
The morphology of the three samples after
annealing (at 500°C) is presented in Figure 1 (bd). The sample DFOM (I) (see Fig. 1b) has quite
big crystallites (average size 72 nm) with irregular
76
morphology. The sample CTAB (II)(see Fig. 1c)
presents small crystallites (average size 45 nm)
without internal defects or pores.
The HRTEM image in Figure 1(e) shows a
WO3 crystallite of CTAB based sample and is
clear that its surface is not fully crystallized, due
to the presence of amorphous layer (1nm in
thickness), possible because of the presence of
surfactant in the system.
Fig. 1. (a) SAED of the WO3 nanomaterial
prepared using DFOM showing WO3 monoclinic
structure. TEM image of the WO3 based
nanomaterials using (b) DFOM sample (c) CTAB
and (d) P123, (e) HRTEM image of a crystallite
oriented in the {100} zone axis, showing
crystallographic facets (CTAB) (f) HRTEM image
of a crystallite, showing insight nanopore (P123).
The morphology of the P123 (III) is quite
different (see Fig. 1d); there are few crystallites
showing crystallographic facets, but all crystallites
have nanopores or mesopores which are generally
centered. These mesopores are between 5 -15 nm
in size and are all faceted, as can be seen in the
HRTEM image in Figure 1(f), where the
mesopore facets are parallel with the (200) planes
of the WO3 structure.
These mesopores are practically empty as the
defocused TEM images show. Internal pores are
connected to the crystallite’s surface with some
extended defects of sub-grain-boundaries
structures. These connections probably permit
also the inside precursor species elimination in
the process of oxide particle formation, and can
be also related to the different sensing properties
of this sample. On the other hand, the internal
surface of the pores is crystallized and clearly
clean, as the HRTEM images show.
In Figure 2 is presented an example of the
response of three sensors towards different
concentrations of NO2 and CO at 250°C. The
base line resistances in presence of dry and
humid air were found to be in the same order of
magnitude for all the sensors. For NO2, the
effects in presence of dry air were higher in
magnitude compared to those at 50% RH; just
the reverse was observed for CO. The sensors
fabricated from materials (I) and (II) have slower
gas response kinetics when compared to that of
sensor III. One should also observe that sensor
III is considerably more sensitive to CO even at
this low temperature. The sensitivity to low
concentration of NO2 is remarkable for all
sensors but the response speed is clearly higher
for sensor III. At 250°C, the dominant response
is the one to NO2 for all sensors. It is clear that
the synthetic strategies applied to obtain various
nanostructural WO3 for sensing application have
a clear impact on the sensing performance and
the relative selectivity towards the analyte gases.
One possible reason is the presence of the pores
in material III; in the case in which the pores are
accessible to the atmospheric gases they can bring
a different type of interaction due to the different
properties of their surfaces [4]. Another influence
the presence of the pores could bring the
practical decrease of the grain size if the grain is
contacted to the atmosphere from outside and
inside (pores).
Sample-I
T = 250°C
500
(ppb)
700
Dry air
Humidity
1000
NO2
300
107
NO2
105
Sensor resistance (Ω)
Selected Results
Sample-II
CO
10
CO
30 70 100
(ppm)
10 ppm CO + 700 ppb NO2
107
105
Sample-III
107
105
0
12
24
36
Time (h)
48
60
72
Fig.2. Gas sensing characteristics of WO3-based
sensors exposed to NO2 (300, 500, 700 and 1000
ppb), CO (10, 30, 70 and 100 ppm)
and NO2/CO (700 ppb/10 ppm) in presence
of dry air and 50% RH.
Due to the proven ability to influence the
morphology and by that the gas sensing performance, the proposed fabrication technologies
have a chance to become a general method for
fabricating gas sensitive materials. Moreover, in
the case of WO3 the performances of the
resulting sensors make them candidates for high
performance gas-sensing devices.
References
[1] M. Niederberger, G. Garnweitner, Chem.
Eur. J. 12, 7282, (2006)
[2] J. Polleux, A. Gurlo, N. Bârsan, U. Weimar,
M. Antonietti, M. Niederberger, Angew.
Chem. Int. Ed., 45, 261, (2006)
[3] I. Jimenez, J. Arbiol, G. Dezanneau, A.
Cornet, J. R. Morante, Sens. and Actuators
B, 93, 475, (2003)
[4] S. Pokhrel, C.E. Simion, V.S. Teodorescu,
N. Bârsan, U. Weimar, Advanced Functional
Materials, Vol. 19(11), 1767-1774, (2009)
77
Selected Results
Biomineralization capability of adherent bio-glass films prepared
by magnetron sputtering
G.E. Stan, I. Pasuk, C.O. Morosanu
in cooperation with
S. Pina, D.U. Tulyaganov, J.M.F. Ferreira
Department of Ceramics and Glass Engineering, CICECO, University of Aveiro, Portugal
Bioactive glass (BG) coatings are considered a
promising alternative in implantology to the
classical hydroxyapatite (HA) ones. It is known
that the prerequisite for biomaterials to bond to
living tissues is the formation of a crystalline HA
layer on their surfaces in physiological media
which significantly enhances their biocompatibility by promoting the osteosynthesis [1].
Compared to HA coatings, the bioactivity of BG
films deposited onto titanium (Ti) substrates
were reported in a few articles, and only one of
these BG related papers refer to magnetron sputtered films. Generally, low values of adhesion for
BG/Ti interfaces were published [2].
This paper concerns with the influence of
radio-frequency magnetron sputtering working
atmosphere upon the biomineralization capability
of the films after 30 days immersion in simulated
body fluid (SBF), which is essential for biomedical
applications. A novel BG composition was studied
(wt %): SiO2 – 40.08, CaO–29.1, MgO–8.96,
P2O5–6.32, CaF2–5.79, B2O3–5.16, and Na2O–
4.59 [3]. The sputtering of BG/Ti coatings was
carried out for ~1 h at a total pressure of 0.3 Pa, in
three different working atmospheres: Ar 100%
(BG2), and 93%Ar+7%O2 (BG4), and
80%Ar+20%O2 (BG5).
The capability of inducing HA formation
onto the coated surfaces after 30 days of SBF
immersion was evaluated by SEM-EDS, XRD
and FTIR measurements.
The adhesion of the as-sputtered BG films,
tested by pull-out method, gave an average
adhesion value of ~75 MPa, with no relevant
differences between the BG samples obtained in
different conditions. This adhesion value is
much higher than the usual ones reported in
literature [4]. These high values of pull-out
78
strength could be attributed to the sputter
cleaning processes of the substrate, done prior to
deposition [5].
The SEM images of the BG samples
immersed for 30 days evidenced the precipitation
of thick and rough coatings occurred for all three
types of samples (Fig.1). The chemically
deposited layer surface shows a spherulitic aspect
for all the samples, which is a specific feature of
in vitro chemically grown HA. The thickness of
the chemically grown layers was determined by
SEM analysis in tilt mode. A thicker chemically
grown apatitic layer was found in case of BG4
structure (~3.9 μm), compared to the initial BG
thickness of ~ 0.4 μm. The BG2 layer increased
after 30 days SBF immersion from ~ 0.5 μm to
1.7 μm, while BG5 from ~0.3 μm up to around
1.2 μm. Thus, the best biomineralization,
correlated with the largest thickness of HA layer
growth, was obtained for the BG4 coating.
Fig. 1: SEM micrographs of bioglass films after
immersion in SBF for 30 days. Left side: SEM-top
view; Right side: SEM-cross view.
Selected Results
XRD revealed that after 30 days of SBF
immersion, all three samples show the
characteristic lines of HA, as large, overlapping
peaks (Fig.2). The XRD patterns of BG2 and
BG5 also evidenced a weak line at 2θ=26.4o,
which agrees with the most intensive line of
quartz-like crystalline silica. The silica line is not
visible in BG4. Based on some X-ray attenuation
considerations taking into account the HA layer
thicknesses measured by SEM, one can suppose
that the observed SiO2 lines originate from a
layer which lies at the bottom side of the
chemically deposited layer, thereby its signal is
attenuated in the covering HA layer.
mechanism because of the higher sodium
content of this film, as evidenced by EDS
analysis. A higher content of Na ions in the
bioglass film leads to a faster hydration of silica,
speeding up the chemical growth of HA. We are
therefore assuming that different Na/Ca ratios
will lead to different biomineralization behaviors.
Fig. 3: FTIR spectra for BG coatings immersed in
SBF for 30 days
Fig.2: GIXRD patterns of the as deposited and the
in vitro tested samples.
The FTIR analysis revealed that all grown
HA layers were obtained hydroxylated and
carbonated as demonstrated by the presence of
strong O–H and (CO3)2- bands (Fig.3).
Hench’s theory [1] states that the first stage
of a bioglass mineralization upon immersion in
SBF involves the rapid exchange of Na+ ions
from the glass for H+ and H3O+ ions from the
solution, which shall initialize the hydrolysis of
the Si-O-Si bonds of the glass structure and the
forming of silanol groups. In a next step the
silanol groups polycondensate forming a silicarich layer at the bioglass surface, which favors the
growth of Ca-P type layers. Therefore, one can
speculate that the higher biomineralization rate
of BG4 film is due to an acceleration of the
chemical processes involved in the bioactivity
In conclusion: adherent BG films with
bioactive properties were synthesized by RF-MS.
During the dissolution-reprecipitation process in
SBF the sputtered BG layer is partially dissolved
and finally we obtain a multilayer structure
containing a bottom BG layer coated by a
quartz-like crystalline thin film and at the top a
carbonated thick film with HA-like crystalline
structure.
References
[1] L.L. Hench, J. Am. Ceram. Soc. 74, 1487
(1991).
[2] G. Goller G, Ceram. Int. 30, 351 (2004).
[3] S. Agathopoulos, D.U. Tulyaganov, J.M.G.
Ventura, S. Kannan, M.A. Karakassides,
J.M.F. Ferreira, Biomaterials 27, 832 (2006).
[4] T. Kokubo, H. Kushitani, C. Ohtsuki, S.
Sakka, T. Yamamuro, J. Mater. Sci-Mater.
Med. 4, 1(1993).
[5] G.E. Stan, C.O. Morosanu, D.A. Marcov, I.
Pasuk, F. Miculescu, G. Reumont, Appl.
Surf. Sci. 255, 9132 (2009).
79
Selected Results
Organic polymeric materials for optical applications
A. Stanculescu, M. Socol, O. Rasoga, N. Preda, L. Mihut,
in cooperation with
F. Stanculescu, I. Ionita, H.V. Alexandru, S. Antohe
University of Bucharest, Faculty of Physics, Bucharest-Magurele, Romania
A.-Maria Albu
University “Politehnica” of Bucharest, Romania
G. Socol, I. N. Mihailescu
National Institute for Laser, Plasma and Radiation Physics, Bucharest-Magurele, Romania
The organic polymers, combining the high
non-resonant non-linear optical (NLO)
properties and the possibilities offered by the
molecular engineering, are an alternative to the
inorganic compounds for optical non-linear
applications. Macroscopic second-order nonlinearity could be induced in polymeric materials
containing
dipolar
chromophores
with
intramolecular
donors–acceptors
groups,
attached as a side chain or intercalated in the
backbone of the polymeric chain.
Functionalised copolymers offer the
possibility to increase the density of
chromophores assuring high values for the nonlinear and electrooptic coefficients. NLO
polymers are easily to process and can be applied
to any substrate promising direct integration
with electronic integrated circuits in single
hybrid optoelectronic packages.
The main contribution obtained by our
research group in this field refers to the
preparation and characterization of monomers
[1] with amidic structure containing different
functional
groups
showing
different
electronegativities [-NH-; -NH-NH-; -NO2]
and derived polymeric compounds such as
aniline
derivative
functionalized
maleic
anhydride–vinyl benzyl chloride copolymer
(MACMSDNA) and aniline derivative functionalised maleic anhydride–methylmethacrylate
copolymer (MAMMADAN) [2]. The distribution of the molecular weight and the
generation of the polymeric structures (MAMMA with a polymerisation degree of 50 and
80
MA-CMS with a polymerisation degree of 25)
have been determined by Gel Permeation
Chromatography and the transformation degree
(grafting efficiency) as a function of the reaction
time by 1H-RMN [1].
Thin films of amidic derivatives (M1) and
(M2), and functionalised copolymers have been
prepared on silicon and quartz substrates by
Matrix Assisted Pulsed Laser Evaporation
(MAPLE) [1, 2].
Fig. 1: UV–VIS spectra of MACMSDNA (POL1,
POL2, POL3 and POL4) and MAMMADNA
(POL5) deposited by MAPLE on quartz [2]
The UV–VIS transmission spectra (Fig. 1)
have shown, for both types of polymeric films, a
large transparency domain (200–1000 nm) and a
structured fundamental absorption edge situated
between 200 nm and 350 nm. This shape is
generated by the strong interaction in the solidstate that favours the splitting of the level (n, π*),
which characterizes the carbonyl and nitrous
groups with non-bonding electrons.
Selected Results
3
1
1
2
3
4
5
6
6
4
2
5
quartz single crystal SHG
quartz powder SHG
M2 thin film SHG
M2 powder SHG
P3 powder TPA
P3 thin film SHG
4
2
3
61
5
Fig.2: Photoluminescence spectra of polymeric thin
films deposited by MAPLE on quartz substrate
(λexcitation=365 nm and λexcitation=380–715 nm) [2].
The emission behaviour of the MACMSDNA
polymer characterised by a lower transformation
degree is close to that of the aniline derivative and
shows a broad peak with a maxim around 590 nm
(Fig. 2) that shifts to higher wavelength when the
preparation conditions are changed.
The emission spectrum of the MAMMADNA
polymer characterised by a higher transformation
degree is different and presents a maximum around
460 nm.
Fig. 3: SEM image of POL1/silicon film [2]
SEM image indicates an uniform
morphology on relatively large area of the films
characterised by droplets type structures with
dimension <0.1 mm (Fig. 3).
Fig. 4: Optical non-linear effects in the synthesized
monomer and functionalized copolymer: second
harmonic emission (SHG) and emission generated
by two photons absorption (TPA) [1].
The second harmonic emission evidenced in
monomer powder and thin films is generated by
the high differences in the electronegativities of
the groups situated in para positions [-NH-/NH-NH-] and [-NO2] and the supplementary
highly polarisable nitro group situated in
position ortho position that introduces an
asymmetry of the cloud of π electrons and a
strong inductive and mezomeric effect.
The second harmonic emission (Fig.4)
observed in MAPLE thin films prepared from
2,4 dinitroaniline functionalized (MA-CMS)
copolymer, is sustained by a combined effect of
the asymmetry of the side substituent groups and
polymeric backbone that favours a noncentrosymmetric packing of the molecules.
The peak situated between 500–600 nm is
attributed to a strong luminescence emission
excited by a two photon absorption mechanism.
References
[1] A. Stanculescu, O. Rasoga, N. Preda, M.
Socol, F. Stanculescu, I. Iulian, A.-M. Albu,
G. Socol, Ferroelectrics, 389, 159 (2009)
[2] G. Socol, I.N. Mihailescu, A.-M. Albu, S.
Antohe, F. Stanculescu, A. Stanculescu, L.
Mihut, N. Preda, M. Socol, O. Rasoga
Applied Surface Science 255, 5611 (2009)
81
Selected Results
Fast TEM specimen preparation of oxide films deposited on Si wafers
V.S.Teodorescu
in cooperation with
M-G.Blanchin
LPMCN, Univ-Lyon, France
Structural investigations by TEM (transmission electron microscopy) for thin films
deposited on silicon wafers are required in an
increasing number of applications. Plan-view and
especially cross-section (XTEM) observations are
generally needed.
Standard XTEM specimen preparation
involves several operations such as cutting,
polishing and ion milling. This procedure is
rather complicated and always time consuming.
Data about the thickness, the morphology
and the structure of the film interface with the
silicon substrate can be obtained after only a few
minutes of specimen preparation, by a new
method proposed by us [1].
This method is effective for films having
thickness between 10 and 100 nm and strong
adherence to the silicon substrate. Here ion
milling is not necessary.
Our method can be related in a microscopic
way to the cleavage preparation methods [2,3]
and can be also considered as a development of
the extraction replica technique [4]. This method
can be possibly extended to oxide films on hard
substrates with well defined cleavage planes, but
hardly applies to metal or other soft material
films.
Different types of fragments can be obtained
by scratching the surface of a film deposited on a
silicon wafer substrate using a pointed diamond
tip. The majority of the fragments will be
detached only from the film or only from the
silicon substrate, but some contain pieces from
both the film and the substrate.
Two cases are interesting. The first case
consists of thin flakes, detached almost parallel to
the film surface, as sketched in Fig.1a. Such
fragments can be used for plan-view TEM
imaging.
82
The second case is more interesting. If the
scratching direction is almost parallel to the
Si<110> direction in the (100)Si wafer plane,
there is a high probability of obtaining microcleavage fragments as sketched in Fig.1b. The
TEM observations from thin edges of such flakes
can provide similar structural data as from the
XTEM specimens.
Fig.1: Schematic view of the micro-fragments
morphology: (a) - micro-fragment allowing planview investigations; (b) - micro-cleavage fragment
allowing cross-section investigations.
Fig.2: Schematic view of the two steps of the
specimen grid preparation.
Selected Results
The TEM grid is prepared in two steps, as
shown schematically in Fig.2. In the first step, a
drop of distilled water is put on the film surface
in the region where we intend to scratch. A holey
carbon grid is positioned nearby having a carbon
layer on the top. Then, the scratching operation
is made gently in the desired direction inside the
water drop using a very thin diamond tip. In the
second step, the grid is gently slid under the
water drop using tweezers. After the water drop
has dried, the grid is ready to be used for TEM
observations.
The procedure described above has been
successfully applied to the case of HfO2 sol-gel
film investigations. Fig.3 shows a film fragment
(as inFig.1a) and the corresponding SAED
pattern.
Fig.3: Fragment of the HfO2 sol-gel film and the
corresponding SAED pattern, in plan-view
orientation (Si[100] zone axis)
This method for obtaining plan-view
specimens is also effective for the case of thin
oxide films deposited on glass or quartz
substrates.
Fig.4: Micro-cleavage fragment in two tilted
orientations: (a) cross-section orientation, and (b)
tilted by 65°, close to a plan-view orientation.
cleavage process. Fig.4 shows such a fragment in
two different orientations.
Fig.5: XTEM-like image of a fragment from a
five-layer HfO2 sol-gel film deposited on silicon
substrate.
This kind of fragment also enables
investigation of quite thick films. The
morphology of a five-layer sol-gel film is clearly
revealed in Fig.5.
The probability of finding plan-view-like
fragments is high. Practically, it is possible to
find several good fragments on a grid by
exploring in low-magnification mode, without
using the goniometer tilt facilities.
References
[1] V.S. Teodorescu and M.G. Blanchin,
Microscopy and Microanalysis 15, 15-19,
2009
[2] J.P. McCaffrey, Ultramicroscopy 38,149157, 1991
[3] S. Sunder, C.A. Faunce, S.E. Donnelly,
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[4] I.N. Mihailescu, A. Lita, V.S. Teodorescu,
E. Gyorgy, R. Alexandrescu, A. Luches,
M. Martino, A. Barborica, J Vacuum Science
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.
The most useful information about the thin
film structure is obtained using the “crosssection-like” fragments resulting from the micro83
84
Publications
and Presentations
85
Journals and books
Publications and presentations
BOOKS
1. Ciurea ML, Iancu V
Chap 5: Quantum confinement in nanometric structures in New Trends in Nanotechnology and
Fractional Calculus Applications
Eds. Baleanu, Dumitru; Guvenc, Ziya B.; Machado, J. A. Tenreiro, Springer, The Netherlands,
ISBN: 978-90-481-3292-8, (14pp), (2009)
2. Feder M
Prepararea feritelor spinelice policristaline
In: Ferite de cobalt magnetostrictive,
Chapter II, pages 37-101, edited by Caltun, O. F., Ed. Universitatii Al. I. Cuza, Iasi, Romania
(2009)
3. Lăzărescu MF, Manea AS, Logofătu C, Ghita RV, Cotarlan C
Metode structurale şi optice pentru studiul proprietăţilor suprafeţelor şi interfeţelor (Structural and
optical methods for the study of surfaces and interfaces properties)
Edit. ELECTRA, 144 pag., (2009)
4. Popescu M, Velea A
Rigidity and Boolchand intermediate phases in nanomaterials
In: Boolchand intermediate Phases: Glass formation ability and average electronegativity Chapter
16, pages 413 – 430, edited by I. Micoulaut and M. Popescu, INOE Publication House,
Bucuresti, Romania (2009)
5. Sima M, Sima Ma, Visan T
Template synthesis of metallic and semiconductors micro and nanowires in porous membranes
In: Electrochemistry and Corrosion, vol 4, chapter 5, pages 241-268, edited by T. Visan,
Politehnica Press, Bucuresti, Romania (2009)
86
Journals and books
PAPERS IN ISI RANKED JOURNALS (with Impact Factor)
1.
Alexandrescu R, Scarisoreanu M, Morjan I, Birjega R, Fleaca C, Luculescu C, Soare I, Cretu O,
Negrila CC, Lazarescu N, Ciupina V
Preparation and characterization of nitrogen-doped TiO2 nanoparticles by the laser pyrolysis of
N2O-containing gas mixtures
Applied Surface Science, 255(10), (2009), pp. 5373-5377
2.
Amarande L, Miclea C, Tanasoiu T, Iuga A, Cioangher MC, Trupina L, Grecu MN, Pasuk I
Effect of nickel-niobium Co-doping on structural, electromechanical and dielectric properties of
lead titanate ceramics Conference Information: 18th IEEE International Symposium on
Applications of Ferroelectrics, AUG 23-27, 2009 Xian, PEOPLES R CHINA
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 56(9), (2009), pp. 17921798
3.
Apetrei R, Catrinescu C, Mardare D, Teodorescu CM, Luca D
Photo-degradation activity of sputter-deposited nitrogen-doped titania thin films, Conference
Information: 2nd International Symposium on Transparent Conducting Oxides, OCT 22-26,
2008 Crete, GREECE
Thin Solid Films, 518(4), (2009), pp. 1040-1043
4.
Awaji S, Inoue T, Takahashi K, Badica P, Nishijima G, Watanabe K
Current transport mechanism and control of the n-value for Ag/Bi2212 wires and tapes
IEEE Transactions on Applied Superconductivity, 19(3), (2009), pp. 3071-3075
5.
Baibarac M, Baltog I, Velula T, Pasuk I, Lefrant S, Gautier N
TitlZnO particles of wurtzite structure as a component in ZnO/carbon nanotube composite
Journal of Physics-Condensed Matter, 21(44), (2009), pp. 445801
6.
Baibarac M, Baltog I, Mihut L, Mevellec JY, Lefrant S
Electropolymerization of N-ethylcarbazole on single walled carbon nanotubes-cyclic
voltammetry, Raman and FTIR studies, Conference Information: 2nd ChemOnTubes
International Conference, APR 06-09, 2008 Zaragoza, SPAIN
Journal of Nanoscience and Nanotechnology, 9(10), (2009), pp. 6195-6203
7.
Baibarac M, Baltog I, Lefrant S
Photoluminescence and Raman spectroscopy studies on polyaniline/PbI2 composite
Journal of Solid State Chemistry, 182(4), (2009), pp. 827-835
8.
Baibarac M, Baltog I, Lefrant S
Raman spectroscopic evidence for interfacial interactions in poly(bithiophene)/single-walled
carbon nanotube composites
Carbon, 47(5), (2009), pp. 1389-1398
9.
Baibarac M, Baltog I, Scocioreanu M, Lefrant S, Mevellec JY
Vibrational properties of the polyindole/single-walled carbon nanotubes composite
electrochemical synthesized
Synthetic Metals, 159, (2009), pp. 2550-2555
10. Baltog I, Baibarac M, Lefrant S, Gomez-Romero P
Surface enhanced Raman scattering studies on poly(3, 4-ethylene dioxythiophene)/single-walled
carbon nanotubes composites and their application to rechargeable lithium batteries, Conference
Information: 2nd ChemOnTubes International Conference, APR 06-09, 2008 Zaragoza,
87
Journals and books
SPAIN
Journal of Nanoscience and Nanotechnology, 9(10), (2009), pp. 6204-6209
11. Baltog I, Baibarac M, Lefrant S
Quantum well effect in bulk PbI2 crystals revealed by the anisotropy of photoluminescence and
Raman spectra
12. Bartolomé J, Filoti G, Kuncser V, Schinteie G, Mereacre V, Anson C, Powell A, Clerac R, Prodius
D, Turta C
Magnetostructural correlations in the tetra-nuclear new series of {Fe3LnO2} “butterfly”core
clusters: a magnetic and Mössbauer spectroscopic study
Phys. Rev. B, (2009), pp. 80014430
13. Bazavan R, Ion L, Socol G, Enculescu I, Bazavan D, Tazlaoanu C, Lorinczi A, Mihailescu IN,
Popescu M, Antohe S
Optical properties of pulsed-laser deposited ZnO thin films
Journal of Optoelectronics and Advanced Materials, 11(4), (2009), pp. 425-428
14. Bibicu I, Nicolescu G, Cretu C
A versatile gas-flow proportional counter for Mössbauer spectroscopy
Hyperfine Interactions, 192(1), (2009), pp. 85-91
15. Birjega R, Vizireanu SI, Dinescu G, Nistor LC, Ganea R
The effect of textural properties of the gamma-Al2O3:Ni catalyst template on the
nanostructured carbon grown by PECVD, Conference Information: 2nd International
Conference on Nano-structures Self-Assembling (NanoSeA2008), JUL 07-10, 2008 Univ Rome
Tor Vergata, Rome, ITALY
Superlattices and Microstructures, 46(1-2), (2009), pp. 297-301
16. Borza VN, Neacsu E, Nistor C, Ianchis R, Popescu N, Mercioniu I
Human albumin nanospheres labelled with (tc)-t-99m
Journal of Labelled Compounds & Radiopharmaceuticals, 52(7-8), (2009), pp. 263-263
17. Carp O, Patron L, Culita DC, Budrugeac P, Feder M, Diamandescu L
Thermal analysis of two types of dextran-coated magnetite
J. Therm. Anal. Calorim, DOI 10. 1007/s, (2009), pp. 10973-009-0593-3
18. Cernea M
Direct synthesis of Y doped BaTiO3 powder by sol-precipitation method
19. Chaboy J, Laguna-Marco MA, Piquer C, Boada R, Plugaru N, Maruyama H, Kawamura N
Origin of the X-ray magnetic circular dichroism at the L-edges of the rare-earths in RxR ' Al-1x(2) systems
Journal of Synchrotron Radiation, 16, (2009), pp. 405-412
20. Constantinescu C, Emandi A, Vasiliu C, Negrila C, Logofatu C, Cotarlan C, Lazarescu M
Thin films of Cu(II)-o, o '-dihydroxy azobenzene nanoparticle-embedded polyacrylic acid (PAA)
for nonlinear optical applications developed by matrix assisted pulsed laser evaporation
(MAPLE)
88
Journals and books
21. Cotirlan C, Logofatu C, Negrila CC, Ghita RV, Manea AS, Lazarescu MF
XPS analysis of n-GaP(111) native and etched surfaces
Journal of Optoelectronics and Advanced Materials 11(4), (2009), pp. 386-390
22. Craciun D, Socol G, Stefan N, Miroiu M, Mihailescu IN, Galca AC, Craciun V
Structural investigations of ITO-ZnO films grown by the combinatorial pulsed laser deposition
technique
23. Crisan A, Sarkar A, Mikheenko P, Dang VS, Kechik MMA, Abell JS
Improvement of pinning force and critical current density in thick YBa (2) Cu (3) O (7-delta)
films grown on SrTiO (3) substrates decorated with LaNiO (3) nanodots
Journal of Superconductivity and Novel Magnetism, 22(7), (2009), pp. 631-636
24. Crisan A, Kechik MMA, Mikheenko P, Dang VS, Sarkar A, Abell JS, Paturi P, Huhtinen H
Critical current density and pinning potential in YBa2Cu3O7-delta thick films ablated from a
BaZrO3-doped nanocrystalline target,
Superconductor Science & Technology, 22(4), (2009), pp. 045014
25. Cui W, Mikheenko P, Yu LM, Button TW, Abell JS, Crisan A
YBa2Cu3O7-x thin films by citrate-based non-fluorine precursor
Journal of Superconductivity and Novel Magnetism, 22(8), (2009), pp. 811-815
26. Enculescu M
Growth and optical characteristics of coumarin 6 doped potassium hydrogen phthalate (KAP)
crystals
Optical Materials, 32(2), (2009), pp. 281-285
27. Endo K, Badica P
Bi2Sr2Ca2Cu3O10 superconducting thin films on substrates with large film-substrate lattice
mismatch and different film-substrate lattice mismatch anisotropy
Crystal Growth & Design, 9(1), (2009), pp. 391-394
28. Endo K, Badica P, Kado H
Growth of non-c-axis BSCCO superconductor-insulator heterostructures
IEEE Transactions on Applied Superconductivity, 19 (3): Part 3 JUN, (2009), pp. 3439-3442
29. Epurescu G, Vlad A, Bodea MA, Vasiliu C, Dumitrescu O, Niciu H, Elisa M, Siraj K, Pedarnig JD,
Bauerle D, Filipescu M, Nedelcea A, Galca AC, Grigorescu CEA, Dinescu M
Pulsed-laser deposition of smooth thin films of Er, Pr and Nd doped glasses
30. Feigl L, Pippel E, Pintilie L, Alexe M, Hesse D
Chromium doping of epitaxial PbZr0. 2Ti0. 8O3 thin films
Journal of Applied Physics, 105(12), (2009), pp. 126103
31. Filoti G, Palade P, Lupu D, Stromberg F, Schinteie G, Ardelean O, Kuncser V
Iron containing 3d-4f compounds: Effect of alternative processing on local interactions and
storage properties, Conference Information: 16th International Conference on Solid
Compouinds of Transition Elements, JUL 26-31, 2008 Dresden, GERMANY
Journal of Alloys and Compounds, 480(1), (2009), pp. 157-160
89
Journals and books
32. Filoti G, Kuncser V, Schinteie G, Palade P, Morjan I, Alexandrescu R, Bica D, Vekas L
Characterization of magnetic nano-fluids via Mössbauer spectroscopy
Hyp. Int. (2009), pp. 19155-60
33. Florea M, Alifanti M, Parvulescu VI, Mihaila-Tarabasanu D, Diamandescu L, Feder M, Negrila
C, Frunza L
Total oxidation of toluene on ferrite-type catalysts, Conference Information: 8th European
Workshop Meeting on Selective Oxidation, AUG 26-31, 2007 Turku, FINLAND
Catalysis Today, 141(3-4), (2009), pp. 361-366
34. Frunza L, Frunza S, Poterasu M, Beica T, Kosslick H, Stoenescu D
Composites containing confined n-octyl-cyanobiphenyl: Monomer and dimer species in the
surface layer by in situ FTIR spectroscopy
Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy, 72(2), (2009), pp. 248-253
35. Gingasu D, Mindru I, Marinescu G, Patron L, Ghica C
Ultrafine particles of ZnGa2O4 obtained by solution combustion and complexation methods
Journal of Alloys and Compounds, 481(1-2), (2009), pp. 890-895
36. Gingaşu D, Mîndru I, Patron L, Diamandescu L, Cizmaş CB, Firăstrău I
Lithium ferrites obtained by thermal decomposition of ureate complex compounds
Revue Roumaine de Chimie, 54(8), (2009), pp. 699–704
37. Girtan M, Dabos-Seignon S, Stanculescu A
On morphological, structural and electrical properties of vacuum deposited pentacene thin films
Vacuum, 83(9), (2009), pp. 1159-1163
38. Glucose D, Covaliu CI, Jitaru I, Diamandescu L, Cristea C
Complex compounds of 3d ions with Deoxy Iron Complex
Rev. Chim. Bucharest, 60 (11), (2009), pp. 1141- 1145
39. González JA, Andrés JP, Toro DE JA, Muñiz P, Muñoz T, Crisan O, Binns C, Riveiro JM
Co–CoO nanoparticles prepared by reactive gas-phase aggregation
Journal of Nanoparticle Research 11, (2009), pp. 2105-2111
40. Gudmundsson V, Gainar C, Tang CS, Moldoveanu V, Manolescu A
Time-dependent transport via the generalized master equation through a finite quantum wire
with an embedded subsystem
New Journal of Physics, 11, (2009), pp. 113007
41. Haeften von K, Binns C, Brewer A, Crisan O, Howes PB, Lowe MP, Sibbley-Allen C, Thornton Sc
A novel approach towards the production of luminescent silicon nanoparticles: sputtering, gas
aggregation and co-deposition with H2O
European Physical Journal D 52 (1-3), (2009), pp. 11-14
42. Husanu AM
Electron-phonon interaction in zinc oxide. Plasmon-optical phonon coupled modes
Physica Status Solidi B-Basic Solid State Physics, 246(1), (2009), pp. 87-91
43. Industnyi IZ, Popescu M, Lőrinczi A, Sava F, Min’ko VI, Shepeliavyi PE, Dan’ko V A
Fabrication of submicrometer periodic structure using interference lithography and two-layer
chalcogenite photoresistance
Journal of Optoelectronics and Advanced Materials, 11, (2009) pp. 1967-1971
90
Journals and books
44. Isopescu R, Mateescu C, Mihai M, Dabija G
The effects of organic additives on induction time and characteristics of precipitated calcium
carbonate
Chem. Eng. Res. Des., doi:101016/j. cherd. 2009. (2009), pp. 10002
45. Kechik MMA, Mikheenko P, Sarkar A, Dang VS, Babu NH, Cardwell DA, Abell JS, Crisan A
Artificial pinning centres in YBa2Cu3O7-delta thin films by Gd2Ba4CuWOy nanophase
inclusions, Conference Information: International Conference on Superconductivity and
Magnetism, AUG 25-29, 2008 Side, TURKEY
Superconductor Science & Technology, 22(3), (2009), pp. 034020
46. Kuncser V, Schinteie G, Palade P, Mustata I, Lungu CP, Stefan N, Chiriac H, Vladoiu R,
Filoti G
Spin configurations and interfacial diffusion in exchange bias and spin valve systems with Ir–Mn
antiferromagnetic pinning layers
Hyp. Int. 191, (2009), pp. 135-40
47. Lazanu S, Ciurea ML, Lazanu I
Semiconductor detectors for high radiation fields: microscopic processes in materials and the
control of device parameters
Journal of Optoelectronics and Advanced Materials, Vol 11 (12), (2009), pp. 2150 – 2154
48. Lazarescu V, Scurtu R, Lazarescu MF, Toader AM, Volanschi E, Santos E, Jones H, Gotz G,
Bauerle P
Potential-induced conformational changes in an alpha-CN-terthiophene thiolate film on
GaAs(110)
Langmuir, 25(11), (2009), pp. 6522-6531
49. Lefrant S, Baltog I, Baibarac M
Optical advanced spectroscopic techniques for the study of nano-structured materials such as
carbon nanotubes
Journal of Nanoelectronics and Optoelectronics, 4(2), (2009), pp. 203-206
50. Lefrant S, Baibarac M, Baltog I
Raman and FTIR spectroscopy as valuable tools for the characterization of polymer and carbon
nanotube based composites
Journal of Materials Chemistry, 19(32), (2009), 5690-5704
51. Lefrant S, Baltog I, Baibarac M
Optical advanced spectroscopic techniques for the study of nano-structured materials:
Applications to carbon nanotubes
Synthetic Metals, 159, (2009), pp. 2173–2176
52. Lungu GA, Teodorescu CM
Band ferromagnetism in systems of variable dimensionality II: the two-dimensional finitetemperature case
53. Lupu D, Biris AR, Watanabe F, Li ZR, Dervishi E, Saini V, Xu Y, Biris AS, Baibarac M, Baltog I
Synthesis of narrow diameter distribution carbon nanotubes on ZnO supported catalysts
Chemical Physics Letters, 473(4-6), (2009), pp. 299-304
91
Journals and books
54. Lupu D, Biriş AR, Baltog I, Baibarac M, Kuncser V, Schinteie G, Valeanu M, Lefrant S, Biris
AS, Mişan I, Filoti G
Carbon nanotubes from ethanol on Fe-Co/MgO catalysts and related interface phenomena
Journal of Optoelectronics and Advanced Materials, 11, (3), , (2009), pp. 338 – 347
55. Mateescu I, Georgescu S, Iliescu B, Enculescu I, Georgescu R, Oproiu C, Ghita G
Influence of ionizing radiations (electrons and gamma) on the electrical characteristics of LGS
resonators Conference Information: 9th European Conference on Applications of Polar
Dielectrics (ECAPD-9), AUG 25-29, 2008 Rome, ITALY
Ferroelectrics, 389, (2009), pp. 25-31
56. Manaila-Maximean D, Rosu C, Zgura I, Frunza L, Stoenescu D
Study of ester-type liquid crystals by TSDC and optical investigations
Molecular Crystals and Liquid Crystals, 512, (2009), pp. 2004-2012
57. Mereacre V, Prodius D, Turta C, Shova S, Filoti G, Bartolomé J, Clérac R, Anson CE, Powell AK
The synthesis, structural characterization, magnetochemistry and Mössbauer spectroscopy of
[Fe3LnO2(CCl3COO)8H2O(THF)3] (Ln = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Lu and Y,
Polyhedron, 28 (2009), pp. 3017-28
58. Miclea CF, Mota AC, Sigrist M, Steglich F, Sayles TA, Taylor BJ, McElroy CA, Maple MB
Vortex avalanches in the noncentrosymmetric superconductor Li2Pt3B
Physical Review B, 80(13), (2009), pp. 132502
59. Mihai M, Turto Di, Isopescu R, Mateescu C, Chilibon I
Calcium carbonate synthesis in ultrasonic field
Rev. Chim. Bucharest, 60, (2009), pp. 626-631
60. Mikheenko P, Sarkar A, Dang VS, Tanner JL, Abell JS, Crisan A
c-Axis correlated extended defects and critical current in YBa2Cu3Ox films grown on Au and
Ag-nano dot decorated substrates
Physica C-Superconductivity and its Applications, 469(14), (2009), pp. 798-804
61. Mikheenko P, Sarkar A, Dang VS, Tanner JL, Kechik MMA, Abell JS, Crisan A
Pinning centers induced in YBCO films by nano-dots in substrate decoration and quasisuperlattice approaches
IEEE Transactions on Applied Superconductivity, 19(3), (2009), pp. 3491-3494
62. Misirlioglu IB, Pintilie L, Alexe M, HesseD
Influence of long-range dipolar interactions on the phase stability and hysteresis shapes of
ferroelectric and antiferroelectric multilayers
Journal of Materials Science 44 (19) Special Issue: Sp. Iss. SI, (2009), pp. 5354-5363
63. Miu L
Possible influence of two-band superconductivity on the behaviour of the second magnetization
peak in La2-xSrxCuO4 single crystals Conference Information: 21st International Symposium
on Superconductivity, OCT 27-29, 2008 Tsukuba, JAPAN
Physica C-Superconductivity and its Applications, 469(15-20), (2009), 1136-1139
64. Moldoveanu V, Manolescu A, Gudmundsson V
Theoretical investigation of modulated currents in open nanostructures
Physical Review B, 80 (20), (2009), pp. 205325
92
Journals and books
65. Moldoveanu V, Manolescu A, Gudmundsson V
Geometrical effects and signal delay in time-dependent transport at the nanoscale
New Journal of Physics, 11, (2009), pp. 073019
66. Moldoveanu V, Dinu IV, Tanatar B
Fano effect in a double T-shaped interferometer
European Physical Journal B, 67(2), (2009), pp. 231-238
67. Moldoveanu V, Tanatar B
Coulomb drag in parallel quantum dots
EPL, 86(6), (2009), pp. 67004
68. Munteanu C, Ionescu NI, Feder M, Diamandescu L, Caldararu M
Electrical properties of iron oxide as a catalyst for deep propane oxidation
Revue Roumaine de Chimie, 54 (11-12), (2009), pp. 1057-1064
69. Neculoiu D, Muller A, Deligeorgis G, Dinescu A, Stavrinidis A, Vasilache D, Cismaru AM, Stan
GE, Konstantinidis G
AlN on silicon based surface acoustic wave resonators operating at 5 GHz
Electronics Letters, 45(23 ), (2009), pp. 1196-1197
70. Nedelcu L, Toacsan MI, Banciu MG, Ioachim A
Dielectric properties of paraelectric Ba1-xSrxTiO3 ceramics, Conference Information: 9th
European Conference on Applications of Polar Dielectrics (ECAPD-9), AUG 25-29, 2008
Rome, ITALY
71. Nistor SV, Nistor LC, Stefan M, Mateescu CD, Birjega R, Solovieva N, Nikl M
Synthesis and characterization of Mn2+ doped ZnS nanocrystals self-assembled in a tight
mesoporous structure, Conference Information: 2nd International Conference on Nanostructures Self-Assembling (NanoSeA2008), JUL 07-10, 2008 Univ Rome Tor Vergata, Rome,
ITALY
Superlattices and Microstructures, 46(1-2), (2009), pp. 306-311
72. Nistor SV, Stefan M
In-depth investigation of EPR spectra of Mn2+ ions in ZnS single crystals with pure cubic
structure, Conference Information: International Conference on Nanoscience and
Nanotechnology, FEB 25-29, 2008 Melbourne, AUSTRALIA
73. Pintilie I, Lindstroem G, Junkes A, et al.
Radiation-induced point- and cluster-related defects with strong impact on damage properties of
silicon detectors
Nuclear Instruments & Methods in Physics Research Section A-Accelerators Spectrometers Detectors
and Associated Equipment, 611 (1), (2009), pp. 52-68
74. Pintilie L, Dragoi C, Chu YH, Martin LW, Ramesh R, Alexe M
Orientation-dependent potential barriers in case of epitaxial Pt-BiFeO3-SrRuO3 capacitors
Applied Physics Letters, 94(23), (2009), pp. 232902
75. Pintilie L
Advanced electrical characterization of ferroelectric thin films: facts and artifacts
93
Journals and books
76. Pintilie L, Dragoi C, Stancu V, Pintilie I
The influence of the electrode type on the electric-ferroelectric properties of sandwich PbZr0.
2Ti0. 8O3-BiFeO3-PbZr0. 2Ti0. 8O3 structure, 9th European Conference on Conference
information: Applications of Polar Dielectrics (ECAPD-9), AUG 25-29, 2008 Rome, ITALY
77. Pokhrel S, Simion CE, Teodorescu VS, Bârsan N, Weimar U
Synthesis, mechanism, and gas-sensing applications of surfactants tailored from tungsten oxide
nanostructures
Advanced Functional Materials, Vol. 19(11), (2009), pp. 1767-1774
78. Polosan S
Characterization of BGO glass-ceramic materials, Conference Information: International
Symposium on Non-Oxide and New Optical Glasses, APR 20-25, 2008 Univ Montpellier 2,
Inst Charles Gerhard, Montpellier, FRANCE
Journal of Non-Crystalline Solids, 355(37-42), (2009), pp. 1900-1903
79. Popa M, Diamandescu L, Vasiliu F, Teodorescu CM, Cosoveanu V, Baia M, Feder M, Baia L,
Danciu V
Synthesis, structural characterization, and photocatalytic properties of iron-doped TiO2 aerogels
Journal of Materials Science, 44(2), (2009), pp. 358-364
80. Popescu FF, Bercu V, Barascu JN, Martinelli M, Massa CA, Pardi LA, Stefan M, Nistor SV, Nikl
M, Bohacek P
Study of the ground multiplet of Kramers rare earth ions in solid matrices by multifrequency
electron paramagnetic resonance spectroscopy: Nd3+ in PbWO4 single-crystals
Journal of Chemical Physics, 131(3), (2009), pp. 034505
81. Popescu M, Sava F, Lorinczi A
A new model for the structure of chalcogenide glasses: The closed cluster model, Conference
Information: International Symposium on Non-Oxide and New Optical Glasses, APR 20-25,
2008 Univ Montpellier 2, Inst Charles Gerhard, Montpellier, FRANCE
Journal of Non-Crystalline Solids, 355 (37-42), (2009), 1815-1819
82. Popescu M, Croitoru N
Amorphous research in Romania: Past, present and latest results
Physica Status Solidi B-Basic Solid State Physics, 246(8), (2009), pp. 1786-1793
83. Popescu M, Sava F, Lorinczi A, Velea A, Vlcek M, Jain H
Modelling of dissolution kinetics of thin amorphous chalcogenide films
Philosophical Magazine Letters, 89(6), (2009), pp. 370-376
84. Popescu M, Sava F, Velea A, Lorinczi A
Crystalline-amorphous and amorphous-amorphous transitions in phase-change materials
Conference Information: International Symposium on Non-Oxide and New Optical Glasses,
APR 20-25, 2008 Univ Montpellier 2, Inst Charles Gerhard, Montpellier, FRANCE
85. Popescu M, Sava F, Lorinczi A, Velea A, Leonovici M, Zamfira S
Silver/amorphous As2S3 heterostructure
Journal of Optoelectronics and Advanced Materials, 11, (2009), pp. 1586-1594
94
Journals and books
86. Popescu M, Petkov K Sava F, Taseeva J, Lorinczi A, Velea A
Matrix-assisted photo-amorphization effect in As40S30Se30 films with silver
87. Preda N, Mihut L, Baibarac M, Baltog I
Intercalation of layered metal iodides with pyridine evidenced by Raman spectroscopy,
Conference Information: Symposium on Raman Scattering in Materials Science, SEP 15-19,
2008 Warsaw, POLAND
Acta Physica Polonica A, 116(1), (2009), pp. 81-83
88. Preda N, Mihut L, Baibarac M, Baltog I, Ramer R, Pandele J, Andronescu C
Films and crystalline powder of PbI2 intercalated with ammonia and pyridine
Journal of Materials Science-Materials in Electronics, 20, Suppl. 1, (2009), pp. 465-470
89. Predoi D, Derible S, Duflo H
Synthesis and ultrasonic characterization of hydroxyapatite ceramic powders
90. Racec PN, Racec ER, Neidhardt H
Evanescent channels and scattering in cylindrical nanowire heterostructures
91. Raileanu M, Crisan M, Dragan N, Crisan D, Galtayries A, Braileanu A, Ianculescu A, Teodorescu
V S, Nitoi I, Anastasescu M,
Sol-gel doped TiO2 nanomaterials: a comparative study
Journal of Sol-Gel Science and Technology 51(3), (2009), pp. 315-329
92. Rasoga OL, Socol M, Stanculescu F,
Charge carrier transport phenomena in some organic heterojunctions
93. Royanian E, Bauer E, Kaldarar H, Galatanu A, Khan RT, Hilscher G, Michor H, Reissner M, Rogl
P, Sologub O, GiesterG, Goncalves AP
The formation, structure and physical properties of M2Pd14+xB5−y compounds, with M = La, Ce,
Pr, Nd, Sm, Eu, Gd, Lu and Th
J. Phys.: Condens. Matter, 21 (2009), pp 305401 (12pp)
94. Samide A, Bibicu I, Turcanu E
Corrosion inhibition of carbon steel in hydrochloric acid using N-acetil p-aminobenzene
sulfonamide
Revista de Chimie, 60 (6), (2009), pp. 564-567
95. Samide A, Bibicu I
A new inhibitor for corrosion of carbon steel in hydrochloric acid solution
Revue Roumaine de Chimie, 54(1), (2009), pp. 33-+
96. Samide A, Turcanu E, Bibicu I
Surface analysis of inhibitor films formed by n-(2-hydroxybenzilidene) thiosemicarbazide on
carbon steel in acidic media
Chemical Engineering Communications, 196(9), (2009), pp. 1008-1017
97. Sandu V, Popa S, Ivan I, Plapcianu C, Sandu E, Mihailescu C, Doroftei F
Fabrication and transport properties of manganite-polyacrylamide-based composites
Journal of Nanomaterials 2009, Article ID 429430, (2009), pp. 1-5
95
Journals and books
98. S andu V
Nonmonotonic flux-flow in inhomogeneous superconductors above the percolation threshold
Physica C, 469, (2009), pp. 126–128
99. Sarkar A, Mikheenko P, Dang VS, Abell JS, Crisan A
Enhancing critical current in YBCO thick films: Substrate decoration and quasi-superlattice
approach, Conference Information: 21st International Symposium on Superconductivity, OCT
27-29, 2008 Tsukuba, JAPAN
Physica C-Superconductivity and its Applications, 469(15-20), (2009), pp. 1550-1553
100. Scurtu R, Ionescu NI, Lazarescu M, Lazarescu V
Surface states- and field-effects at p- and n-doped GaAs(111)A/solution interface
Physical Chemistry Chemical Physics, 11(11), (2009), pp. 1765-1770
101. Secu CE, Predoi D, Secu M, Cernea M, Aldica G
Structural investigations of sol-gel derived silicate gels using Eu3+ ion-probe luminescence
102. Secu CE, Sima M
Photoluminescence and thermoluminescence of ZnO nano-needle arrays and films
103. Secu M, Secu CE, Polosan S, Aldica G, Ghica C
Crystallization and spectroscopic properties of Eu-doped CaF2 nanocrystals in transparent
oxyfluoride glass-ceramics, Conference Information: International Symposium on Non-Oxide
and New Optical Glasses, APR 20-25, 2008 Univ Montpellier 2, Inst Charles Gerhard,
Montpellier, FRANCE
104. Sima C, Grigoriu C, Viespe C, Pasuk I, Matei E
Titanium oxide thin films produced by pulsed laser deposition
Journal of Optoelectronics and Advanced Materials, 11(6), (2009), 826-830
105. Socol G, Mihailescu IN, Albu AM, Antohe S, Stanculescu F, Stanculescu A, Mihut L, Preda N,
Socol M, Rasoga O
MAPLE prepared polymeric thin films for non-linear optic applications
106. Stan GE
Adherent functional graded hydroxylapatite coatings produced by sputtering deposition
techniques
107. Stan GE, Morosanu CO, Marcov DA, Pasuk I, Miculescu F, Reumont G
Effect of annealing upon the structure and adhesion properties of sputtered bio-glass/titanium
coatings
108. Stanculescu A, Rasoga O, Preda N, Socol M, Stanculescu F, Ionita I, Albu AM, Socol G
Preparation and characterization of polar aniline functionalized copolymers thin films for optical
non-linear applications Conference Information: 9th European Conference on Applications of
Polar Dielectrics (ECAPD-9), AUG 25-29, 2008 Rome, ITALY
96
Journals and books
109. Sima M, Ion L, Antohe S, Vasile E
Submicron wires with nanosized grain structure
Superlattices and Microstructures, 46(6), (2009), pp. 833-839
110. Tanaka Y, Crisan A, Shivagan DD, Iyo A, Shirage PM, Tokiwa K, Watanabe T, Terada N
Phase diagram of a lattice of pancake vortex molecules, Conference Information: 21st
International Symposium on Superconductivity, OCT 27-29, 2008 Tsukuba, JAPAN
Physica C-Superconductivity and its Applications, 469(15-20), (2009), 1129-1131
111. Tanaka Y, Crisan A
Ambiguity in the statistics of single-component winding vortex in a two-band superconductor
Physica B-Condensed Matter, 404(8-11), (2009), pp. 033-1039
112. Tanasescu S, Grecu MN, Urse M, Teodorescu F, Giurgiu LM, Chiriac H, Totir ND
Effects of dopants and oxygen non-stoichiometry on thermodynamic and magnetic properties of
micro- and nanostructured perovskite type manganites, Conference Information:
Electroceramics XI Conference, AUG 31-SEP 04, 2008 Univ Manchester, Manchester,
ENGLAND
Advances in Applied Ceramics, 108(5), (2009), pp. 273-279
113. Teodorescu VS, Blanchin MG
Fast and simple specimen preparation for TEM studies of oxide films deposited on silicon wafers
Microscopy and Microanalysis, 15(1), (2009), pp. 15-19
114. Tolea M, Dinu IV, Aldea A
Kondo peaks and dips in the differential conductance of a multi-lead quantum dot: Dependence
on bias conditions
115. Trapalis C, Calderon-Moreno JM, Todorova N, Teodorescu VS, Stoica M, Nicolescu M,
Anastasescu M, Gartner M, Zaharescu M
Nitridation and crystallization of titanium oxynitride by thermal treatment of TiO2-anatase
films in NH3
Journal of Optoelectronics and Advanced Materials, 11 (11), (2009), pp. 1810-1814
116. Turcu F, Simon S, Constantinescu S, Grecu N, Iuga D
Structural changes of piezoelectric La3Ga5SiO14 induced by paramagnetic ions revealed by 71Ga
multiple quantum magic angle spinning
Solid State Nuclear Magnetic Resonance, 36(2), (2009), pp. 92-95
117. Vasiliu C, Epurescu G, Niciu H, Dumitrescu O, Negrila C, Elisa M, Filipescu M, Dinescu M,
Grigorescu CEA
Optical and structural investigations on rare earth-doped thin films of phosphate glasses
prepared by pulsed laser deposition, Conference Information: 2nd International Conference on
Optical and Optoelectronic Properties of Materials and Applications, JUL 30-AUG 03, 2007
London, ENGLAND
Journal of Materials Science-Materials in Electronics, 20, (2009), pp. 286-289
118. Vasiliu F, Diamandescu L, Macovei D, Teodorescu CM, Tarabasanu-Mihaila D, Vlaicu AM,
Parvulescu V
Fe- and Eu-doped TiO2 photocatalytical materials prepared by high energy ball milling,
Conference Information: International Symposium on Creation and Control of Advanced
97
Journals and books
Selective Catalysis, JUL 08-12, 2008 Kyoto, JAPAN
Topics in Catalysis, 52(6-7), (2009), pp. 544-556
119. Vasiliu F, Diamandescu L, Macovei D, Teodorescu CM, Nicula R
EXAFS investigation of iron local environment in metal-doped titania photocatalysts prepared
by hydrothermal and high-energy ball milling routes, Conference Information: 2nd
International Conference on Optical and Optoelectronic Properties of Materials and
Applications, JUL 30-AUG 03, 2007 London, ENGLAND
Journal of Materials Science-Materials in Electronics, 20, (2009), pp. 211-215
120. Vasylkiv O, Borodianska H, Badica P, Zhen Y, Tok A
Nanoblast synthesis and consolidation of (La0. 8Sr0. 2) (Ga0. 9Mg0. 1)O3-delta under spark
plasma sintering conditions
Journal of Nanoscience and Nanotechnology, 9(1), (2009), 141-149
121. Velea A, Rusu M, Popescu M
Optical fiber coupling to a laser diode through chalcogenide microlenses
122. Velea A
Tellurium based phase change materials
123. Vizireanu S, Stoica SD, Mitu B, Husanu MA, Galca A, Nistor L, Dinescu G
Radiofrequency plasma beam deposition of various forms of carbon based thin films and their
characterization
124. Zaharescu M, Wittmar A, Teodorescu V, Andronescu C, Wittmar M, Veith M
TiO2-CeO2 nanometric powders prepared by sol-gel method
Zeitschrift fur Anorganische und Allgemeine Chemie 635(12), (2009), pp. 1917-+
125. Zgura I, Moldovan R, Beica T, Frunza S
Temperature dependence of the density of some liquid crystals in the alkyl cyanobiphenyl series,
Crystal Research and Technology, 44(8), (2009), pp. 883-888
98
Journals and books
PAPERS IN ISI JOURNALS 2008 (issued after editing of Annual Report 2008)
1. Buda M, Iordache G, Mokkapati S, Fu L, Jolley G, Tan HH, Jagadish C, Buda Mi
Analytical expression for the quantum dot contribution to the quasistatic capacitance for
conduction band characterization
Journal of Applied Physics Volume: 104 Issue: 2 Article Number: 023713 (2008)
2. Buda M, Iordache G, Mokkapati S, Tan HH, Jagadish C, Stancu V, Botila T
Capacitance spectroscopy study of InGaAs/GaAs quantum dot structures
Journal of Optoelectronics and Advanced Materials, Vol. 10, No. 2, Feb. 18 (2008), pp. 323-327
3. Buda M, Iordache G, Stancu V, Botila T
Characterization of high performance PbS photodetectors
Journal of Optoelectronics and Advanced Materials, Vol. 10, No. 2, Feb. 18 (2008), pp. 306-310
4. Baia L, Baia M, Vasiliu F, Diamandescu L, Peter A, Cosoveanu V, Danciu V
TiO2-Ag porous nanocomposite for advanced photocatalytic processes
NSTI Nanotech 2008, VOL 1, Technical Proceedings, (2008), pp. 381-384
5. Ghita RV, Lazarescu V, Logofatu C, Negrila CC, Lazarescu MF
Electrical characterization of thiols self-assembled layers on GaP structures
Materials Science Semiconductor Processing 11(5) (2008) pp. 394-397
6. Goldenblum A, Stancu V, Buda M, Iordache G, Pintilie I, Negrila C, Botila T
Capacitance-voltage characteristics of heterostructures with high leakage currents
Journal of Applied Physics; Volume: 103 Issue: 5 Article Number: 056107 (2008)
7. Ion L, Enculescu I, Antohe S
Physical properties of CdTe nanowires electrodeposited by a template method, for photovoltaic
applications
8. Manaila-Maximean D, Rosu C, Donescu D, Frunza S
Synthesis and electro-optical studies on composite material: functionalized copolymer
particles/nematic liquid crystal
Conference Information: Korea-Japan Joint Forum on Organic Materials for Electonics and
Photonics, SEP 27-29, 2007 Korea Univ, Seoul, SOUTH KOREA
Molecular Crystals and Liquid Crystals, 495, (2008), pp. 510-520
9. Matei E, Sima M, Enculescu I, Sima M, Enculescu M, Neumann R, Granville S, J. P Ansermet.
Preparation and properties of transition metal doped ZnO nanowires
ECS Transactions 16 (12), (2008), pp. 41-46
10. Militaru N, Lojewski G, Banciu MG
Microwave compact filters using multilayer structures
Revue Roumaine des Sciences Techniques-Serie Electrotechnique Et Energetique, 53(4), (2008), pp.
463-472
11. Vatasescu-Balcan RA, Predoi D, Costache M
Study of osteoblast interaction with iron oxide nanoparticles coated with dextrin in cell culture
FEBS Journal, 275, (2008), pp. 374-374
99
Journals and books
12. Zoita NC, Besleaga C, Braic L, Mitran T, Vlaicu M
Pyramidal morphology of InN thin films deposited by reactive RF-magnetron sputtering
Optoelectronics and Advanced Materials-Rapid Communications, 2(12), (2008), pp. 796-797
100
Journals and books
PAPERS IN NON-RANKED ISI JOURNALS INDEXED IN WEB OF SCIENCE
1. Baltog I, Baibarac M, Mihut L, Preda N, Velula T, Bucur C, Husanu M
Vibrational properties of polyaniline functionalized PbI2
National Conference of Physics, Sep. 10-13, 2008 Bucharest, Romania
Romanian Journal of Physics, 54(7-8), (2009), pp. 677-688
2. Bazavan D, Bazavan R, Enculescu I, Matei E, Necula C, Ion L, Antohe S
Magnetic properties of NiCu thin films obtained by electrodeposition
3. Beica T, Frunza L, Nistor LC, Zgura I, Dorogan A, Carpus E
Studies on multifunctional textile materials. Image based analysis and classic spectroscopy
4. Beica T, Zgura I, Frunza S, Poterasu M, Moldovan R
Specific interactions of nematic liquid crystals for the alignment on substrates
Journal of Optoelectronics and Advanced Materials – Symposia, 1 (3), (2009), pp. 582-587
5. Bibicu I, Cretu C
Mossbauer backscattering measurements on Eu-151
9th International Balkan Workshop on Applied Physics, Jul. 07-09, 2008 Constanta, Romania
6. Borza V, Neacsu E, Barna CM, Popescu-Pogrion N, Mercioniu I, Nistor C
Labelling of albumin microspheres with 188Re: a possible agent for radiotherapy International
Journal Nano and Biomaterials, Vol. 2, No. 6, (2009), pp. 540 – 546
7. Borza V, Neacsu E, Barna CM, Popescu-Pogrion N, Mercioniu I, Nistor C
Preparation of human serum albumin nanospheres labelled with 188Re
International Journal Nano and Biomaterials, Vol. 2, No. 6, (2009), pp. 547 – 553
8. Boutiuc LM, Dumitru I, Caltun OF, Feder M, Vilceanu V
Coprecipitated cobalt ferrite for sensors
Sensor Letters, 7(3), (2009), pp. 244-246
9. Cazanaru D, Szilagyi A, Ioachim A
Evaluation of the shielding effectiveness of a multimode metallic cavity
Optoelectronics and Advanced Materials-Rapid Communications, 3, (2009), pp. 1235-1242
10. Cernea M, Trupina L, Plapcianu C, Trusca R, Galassi C
Evolution of the surface morphology with temperature, in oxidant atmosphere, of Ba (Ti1xSnx)O-3 (x=0. 13) thin films
Optoelectronics and Advanced Materials-Rapid Communications, 3(9), (2009), 947-950
11. Crisan A, Tanner JL, Mikheenko P, Abell JS
All-self-assembled MgO nanorods and nanowires grown on Au-decorated MgO substrates by
pulsed laser deposition
101
Journals and books
12. Duliu OG, Grecu MN, Cristea C
EPR and X-ray diffraction investigation of some Greek marbles and limestones
Romanian Reports in Physics, 61(3), (2009), pp. 487-499
13. Enculescu M, Trautmann C, Neumann R
Micro- and nanorods of potassium acid phthalate grown in ion-track templates
Gsi Scientific Report 2008, May 2009 Darmstadt, ISSN 0174-0814, (2009), pp. 358
14. Enculescu M, Matei E, Preda N, Enculecu I
Influence of dye concentration on optical properties of rhodamine 6G doped KAP crystals
Optoelectronic and Advanced Materials-Rapid Communications, 3 (11), (2009), pp. 1210-1212
15. Georgescu S, Cotoi E, Voiculescu AM, Toma O, Grecu MN, Borca E, Hodorogea S
Optical and EPR investigations of the thermal treatment effects on YVO4 nanocrystals
16. Husanu AM, Baltog I, Baibarac M, Preda N, Mihut L, Velula T, Bucur C
Absorption and luminescence properties of C-70 aggregates in solvent mixtures, Conference
Information: National Conference of Physics, SEP 10-13, 2008 Bucharest, ROMANIA
17. Lazanu I, Lazanu S
Energy deposited by radiation in solids: registration physics
18. Lazanu I, Chera M, Iordanescu R, Nita C, Lazanu S
From nuclear matter to strange quark matter - some characteristics of the interactions in ordinary
matter, Conference Information: Annual Scientific Conference of the Faculty-of-Physics of the
University-of-Bucharest, JUN 06, 2008 Bucharest, ROMANIA
19. Lazanu S, Ciurea ML, Lazanu I
Point and extended defects in irradiated silicon and consequences for detectors
Physica Status Solidi C 6 (8), (2009), pp. 1974– 1978
20. D. Luca, R. Apetrei, M. Dobromir, V. Dascaleanu, C. M. Teodorescu
An XPS study of RF sputtered Ti1-xFexO2-δ thin films
J. Automation, Mobile Robotics and Intelligent Systems 3, pp. 15-17 (2009).
21. Matei E, Preda N, Enculescu M, Sima M, Sima M, Enculescu I
Optical properties of CdS electrodeposited nanowires
22. Miclea C, Tanasoiu C, Miclea CF, Trupina L, Cioangher M, Miclea CT, Malczanek V, Susu M,
Voicu I, Ivanov A
Structure and properties of (Cu Ca Bi) doped KNN lead-free piezoceramics
23. Popescu M, Savastru D, Popescu A, Miclos S, Lorinczi A, Sava F, Velea A, Baschir L, Ciobanu M,
Matei E, Socol G, Mihailescu IN, Niciu H
Chalcogenide photonic structures
102
Journals and books
24. Preda N, Mihut L, Baibarac M, Baltog I, Husanu M, Bucur C, Velula T
The intercalation of PbI2 with 2, 2'-bipyridine evidenced by photoluminescence, FT-IR and
Raman spectroscopy
Romanian Journal of Physics 54, (7-8), (2009), pp. 667-675
25. Sandu V, Popa S, Ivan I, Plapcianu C, Sandu E, Mihailescu C, Doroftei F
Fabrication and transport properties of manganite-polyacrylamide-based composites
Journal of Nanomaterials, (2009), pp. 429430
26. Sandu V, Popa S, Pasuk I, Enculescu I, Nicolescu MS, Radicescu S
Nanostructured ferrite formation in borosilicate glass
Advanced Materials Research 79-82, (2009), pp. 445-448
27. Sava F, Popescu M
Structural modelling of nano-carbons and nano-chalcogenides
Proceedings of the Romanian Academy Series A-Mathematics Physics Technical Sciences Information
Science, 10(1), (2009), pp. 19-25
28. Sima M, Vasile E, Sima Mariana
Electrochemically deposited thermoelectric Bi2(Se, Te)3 nanowires
Optoelectronics and Advanced Materials-Rapid Communications 3, (2009), pp. 539-542
29. Somma F, Montereali RM, Vincenti MA, Polosan S, Secu M
Radiation induced defects in Pb2+-doped LiF crystals
Physics Proceedia 2, (2009), pp. 211-221
30. Surmeian A, Groza A, Diplasu C, Ganciu M, Teodorescu CM, Tempez A, Chapon P
Photonic molecular effects associated to the sputtering process in a glow discharge optical emission
spectrometer
31. Ungureanu F, Predoi D, Ghita RV, Vatasescu-Balcan RA, Costache M
Characteristics of vacuum deposited sucrose thin films
Interface Controled Organic Thin Films, 1, (2009), pp. 67-71
32. Velea A, Popescu M
Phase change materials: chemical bonding and structural properties
Proceedings of the Romanian Academy Series A-Mathematics Physics Technical Sciences Information
Science, 10(3), (2009), pp. 230-236
103
Conference Proceedings
CONFERENCE PROCEEDINGS
1. Aldea A, Tolea M, Dinu V
Peak-dip crossover of the differential conductance in mesoscopic systems with quantum impurities
In: Proceedings of The International Conference on Low Temperature Physics LT25, J. Phys. : Conf.
Ser. 150, 022001(2009)
2. Alexandru HV, Ioachim A, Toacsan MI, Nedelcu L, Banciu MG, Berbecaru C, Voicu G, Jinga S,
Andronescu E
Ba(Zn1/3Ta2/3)O-3 Ceramics for Microwave and Millimeter-wave Applications
In: 5th Interdisciplinary Transport Phenomena - Fluid, Thermal, Biological, Materials and Space
Sciences, Oct. 14-19, 2007 Univ SE Calif/Rostislaw Kaichew Inst Phys Chem, Bansko, Bulgaria,
Book Series: Annals of the New York Academy of Sciences, 1161, 549-553, (2009)
3. Apetrei R., Negrila C, Macovei D, Dascaleanu V, Teodorescu CM, Mardare D, Luca D
Fabrication and characterization of nano-structured ferromagnetic Ti1-xFexO2 thin films
In: Proceedings of the Nanotechnology 2009 Conference (NANOTECH 2009), Houston, USA, May
2009, Eds. M. Laudon and B. Romanowicz, Vol. 1, pp. 375-378 (2009)
4. Banciu MG, Ioachim A, Mihai IA, Militaru N, Lojewski G
Microwave investigation of constitutive electromagnetic parameters of some left-handed structures
In: Proceedings of the German Microwave Conference, GeMiC 2009, 16-18 March 2009, Munchen,
Germany, 1-4, (2009)
5. Banciu MG, Mihai IA, Militaru N, Lojewski G, Petrescu T
Microwave investigations on some microstrip left-handed structures
In: Proceedings of the 9th International Conference on Telecommunications in Modern Satellite,
Cable and Broadcasting Services 2009 – TELSIKS’09, 7-9 Oct. 2009, Nis, Serbia, 435-438,
(2009)
6. Beica T, Frunza L, Zgura I, Nistor LC, Amariutei V, Dorogan A, Carpus E
Colorimetric characterization of the behavior of thermochromic dye composites imprinted onto
fabrics
In: 2nd International Conference Technical Textiles (TEX TECH II), Conference Brochure, 179-182,
(2009)
7. Bibicu I, Nicolescu G, Cretu C
Mossbauer backscattering measurements on Sn
In: Advanced Topics in Optoelectronics, Microelectronics and Nanotechnnologies Conference,
ATOM-N 2008, 28-31 August, Constanta, ROMANIA, Proc. SPIE, vol. 7297, 7297-65, p.
72971T1-4 (2009)
8. Borza VN, Neacsu E, Nistor C, Ianchis R., Popescu Pogrion N, Mercioniu I
Human albumin nanospheres labelled with (TC)-T-99M
In: 15th Workshop Int. Isotope Society, June 12 – 13, 2008, Bad Soden; JOURNAL OF LABELLED
COMPOUNDS & RADIOPHARMACEUTICALS, Vol: 52 Issue: 7-8, Pages: 263-263 (2009)
9. Ciurea ML, Stavarache I, Lepadatu AM, Iancu V, Dragoman M, Konstantinidis G, Buiculescu R
Investigation of electrical properties of carbon nanotubes
In: Proc. IEEE CN CFP09CAS-PRT, Int. Semicon. Conf. CAS 2009, October 12 – 14, Sinaia,
Romania, 1, 121-124, 2009
104
10. Creţu N, Pop M I, Mercioniu I, Popescu-Pogrion N
An estimation of some mechanical properties of special ceramics for IT-SOFC electrolyte
In: ROCAM 2009, Sixth Int. Edition, Aug. 25-28th, Brasov, Romania (2009)
11. Crisan O, Crisan AD, Skorvanek I, Kovac J
Magnetism and Structural Phase Transformation in Fe/Fe oxide Nanopowders
In: 13th International Conference on Rapidly Quenched and Metastable Materials, AUG 24-29,
2008 Dresden, Germany, Book Series: Journal of Physics Conference Series, Editor(s): Schultz L;
Eckert J; Battezzati L; Stoica M, , 144, 12027-12027, (2009)
12. Enculescu I, Matei E, Vasilache V, Teodorescu CM
Cobalt doped ZnO prepared by electrochemistry: chemistry, morphology, and magnetism
13. Fretwurst E, Januschek F, Klanner R, Perrey H, Pintilie I, Renn F
Study of the Radiation Hardness of Silicon Sensors for the XFEL
In: IEEE Nuclear Science Symposium/Medical Imaging Conference, Oct 19-25, 2008 Dresden,
Germany 2008 Vols 1-9, Book Series: IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD Pages: 1810-1813 (2009)
14. Isopescu R, Mateescu C, Mihai M, Udrea I
Particle size distribution analysis for calcium carbonate precipitation
In: 8th World Congress of Chemical Engineering WCCE -8, Montreal, Canada, 23-27 August, 2009,
ISBN 0-920804-44-6, 6 p., Proceedings USB-Key (2009)
15. Lazanu S, Lazanu I, Lepadatu A, Stavarache I
Defect production in silicon and germanium by low temperature irradiation
In: Proc. IEEE CN CFP09CAS-PRT, Int. Semicon. Conf. CAS 2009, October 12 – 14, Sinaia,
Romania, 2, 379-382, 2009
16. Lovlie LS, Pintilie I, Kumar SCP, Grossner U, Svensson BG, Beljakowa S, Reshanov SA, Krieger M,
Pensl G
Interface States in 4H-and 6H-SiC MOS Capacitors: a Comparative Study between Conductance
Spectroscopy and Thermal Dielectric Relaxation Current Technique
In: 7th European Conference on Silicon Carbide and Related Materials, Sep. 07-11, 2008
Barcelona, Book Series: Materials Science Forum, 615-617, 497-500, (2009)
17. Lojewski G, Militaru M, Banciu MG
Microstrip bandpass filters with a maximum number of attenuation poles
In: Proceedings of the 32nd International Spring Seminar on Electronics Technology, 13-17 May 2009,
Brno, Czech Republic, 1-4, (2009)
18. Lojewski G, Militaru N, Banciu MG
Microwave bandpass filters with multipole couplings, designed using electromagnetic simulations
and linear circuit optimization
In: Proceedings of the International Symposium on Signals, Circuits and Systems ISSCS 2009, 9-10
July 2009, Iasi, Romania, pages 1-4, (2009)
19. Lojewski G, Militaru N, Banciu MG
New topologies for planar microwave band-pass filters with strongly asymmetric characteristics
In: Proceedings of the International Semiconductor Conference, CAS 2009, 12-14 Oct. 2009, Sinaia,
Romania, 323-326 (2009)
105
20. Mateescu CD, Isopescu R, Mihai M
The influence of supersaturation on the synthesis of ultrafine aragonite. Kinetic parameters
estimation
In: 5th International Materials Symposium, MATERIAIS 2009, 5-8 April, Lisbon, Portugal, paper A
108, 6p, CD Proceedings (2009)
21. Miclea C, Tanasoiu C, Miclea CF, Spanulescu I, Cioangher M, Miclea CT
Magnetic Temperature Transducers Made from Copper Based Soft Ferrite
In: 3rd International Conference on Smart Materials, Structures and Systems, Jun 08-13, 2008
Acireale, Italy, SMART MATERIALS & MICRO/NANOSYSTEMS Book Series: Advances in
Science and Technology, 54, 62-69, (2009)
22. Negrila C, Logofatu C, Socol G, Macovei D, Teodorescu C M
Pulsed laser co-deposition of titania with Fe: chemistry, local atomic structure, and lightdependent magnetic properties
23. Negrila CC, Ungureanu F, Ghita RV
Aspects of temperature dependence on Au-Ti/GaAs(SI) Schottky barrier
In: Proceedings of the 2009 32nd International Semiconductor Conference October 12-14 Sinaia,
Romania, CAS 2009, Vol. 2, 455-458 (2009)
24. Pintilie I, Lovlie LS, Irmscher K, Wagner G, Svensson BG, Thomas B
The Influence of Growth Conditions on the Annealing of Irradiation Induced EH6, 7 Defects in
4H-SiC
In : 7th European Conference on Silicon Carbide and Related Materials, Sep. 07-11, 2008
Barcelona, Spain, Book Series: Materials Science Forum, 615-617, 369-372, (2009)
25. Pintilie I, Moscatelli F, Nipoti R, Poggi A, Solmi S, Svensson BG
Analysis of the Electron Traps at the 4H-SiC/SiO2 Interface of a Gate Oxide Obtained by Wet
Oxidation of a Nitrogen pre-Implanted Layer
In: 7th European Conference on Silicon Carbide and Related Materials, Sep. 07-11, 2008
Barcelona, Book Series: Materials Science Forum, 615-617, 533-536, (2009)
Structural modeling of nano-carbons and nano-chalcogenides
In: Proceedings of the Romanian Academy Series A- Mathematics, Physics, Technical Sciences
Information Science, 10, 19-25, (2009)
Phase change materials: Chemical bonding and structural properties
In: Proceedings of the Romanian Academy Series A- Mathematics, Physics, Technical Sciences
Information Science, 10, 333-340, (2009)
28. Secu CE, Secu M, Polosan S, Ghica C
Eu3+-doped BaF2 nanocrystallites in sol-gel derived glass-ceramics
In: Book of Abstracts of the 7th International Conference on Luminescent Detectors and
Transformers of Ionizing Radiation LUMDETR Krakow POLAND (2009)
29. Sima M, Vasile E, Sima Ma, Matei E
Semiconductor Hybrid Structure: Nanowires Embedded in a Matrix from the Same Material
106
To appear in: "ECS Transactions - Vienna, Austria" Volume 25, "Semiconductors, Metal Oxides,
and Composites: Metallization and Electrodeposition of Thin Films and Nanostructures" (2009)
30. Sima Ma, Grecu MN, Sima M, Enculescu I
Growth and Characterization of ZnO:Mn Submicron Wires via Electrodeposition from NitrateLactic Acid Solution
To appear in: "ECS Transactions - Vienna, Austria" Volume 25, "Semiconductors, Metal Oxides,
and Composites: Metallization and Electrodeposition of Thin Films and Nanostructures" (2009)
31. Sorescu M, Diamandescu L, Tomescu A, Krupa S
Designing Mixed Oxides Magnetic Nanoparticles for Sensing Applications
In: Mater. Res. Soc. Symp. Proc., Vol. 1118, K03-03 (2009)
32. Stoica T, Gartner M, Ianculescu A, Anastasescu M, Slav A, Pasuk I, Stoica T, Zaharescu M
Structural and optical properties of sol-gel derived hydroxyapatite films in different stages of
crystallization and densification processes
In: 32nd International Conference on Advanced Ceramics and Composites, Jan. 27-Feb. 01, 2008
Daytona Beach, FL, NANOSTRUCTURED MATERIALS AND NANOTECHNOLOGY II
Book Series: Ceramic Engineering and Science Proceedings, 29(8), 209-216, (2009)
33. Tanatar B, Moldoveanu V
Coulomb drag effect in parallel quantum dots
In: American Institute of Physics Conf. Proc. 1147, 87(2009)
34. Ungureanu F, Predoi D, Ghita RV, Vatasescu-Balcan RA, Costache M
Characteristics of vacuum deposited sucrose thin films
In: Interface Controlled Organic Thin Films, p. 67-71, EMRS-Spring Meeting, Strasbourg 2008,
DOI: 10. 2007/978-3-540-95930-4-11, Springer-Verlag Berlin Heidelberg 2009
CONFERENCE PROCEEDINGS 2008 (issued after editing of Annual Report 2008)
1. Miclea C, Tanasoiu C, Iuga A, Spanulescu I, Miclea CF, Plavitu C, Amarande L, Cioangher M,
Trupina L, Miclea CT, Tanasoiu T
A high performance pzt type material used as sensor for an audio high frequency piezoelectric siren
Conference Information: 31st International Semiconductor Conference 2008, OCT 13-15, 2008
Sinaia, ROMANIA, CAS: 2008 International Semiconductor Conference, Proceedings, 185-188,
(2008)
2. Neamtu J, Teodorescu CM, Georgescu G, Ferre J, Malaeru T, Jitaru I
Structural and magneto-optical properties of co-doped zno thin films prepared by sol-gel method
Proceedings of the Nanotechnology 2008 Conference (NANOTECH 2008), Boston, USA, June
3. Teodorescu CM, Socol G, Negrila C, Luca D, Macovei D
Nanostructured thin layers of vanadium oxides doped with cobalt, prepared by pulsed laser
ablation: structure, chemistry, morphology, and magnetism
Conference Information: Nanotechnology Conference and Trade Show (Nanotech 2008), JUN
01-05, 2008 Boston, MA, NSTI Nanotech 2008, Vol 1, Technical Proceedings - Materials,
Fabrication, Particles, and Characterization, 435-438, (2008)
107
Contributed Presentations
CONTRIBUTED PRESENTATIONS
1.
Aldica GV
Flux jumps anomalous behaviour in FAST-processed MgB2 composites
Romanian Conference on Advanced Materials (ROCAM), Brasov, Romania
25-28.08.2009, Talk
2.
Alexandru HV, Berbecaru C, Ioachim A, Nedelcu L, Toacsan MI, Scarisoreanu N, Jinga S
BZT thin films ceramic for microwave applications
E-MRS 2009 Spring Meeting, Strasbourg, France
26-30.06.2008, Talk
3.
Anastasescu C, Preda S, Teodorescu VS, Zaharescu M
Nanotubes a base de SiO2 et de TiO2 obtenus par voie sol-gel et hydrothermale
Premier Colloque Francophone sur les Materiaux, les Procedes et l’Environnement, Busteni,
Romania
31.05-06.06.2009, Poster
4.
Anastasescu C, Gartner M, Balint I, Anastasescu M, Teodorescu VS, Zaharescu M Multifunctional
SiO2 nanotubes obtained by sol-gel
XV International Sol-Gel Conference SOL-GEL 2009, Porto de Galinhas, Brazilia
23-27.08.2009, Talk
5.
Antohe S, Enculescu I, Ion L
Progress in photovoltaic cells based on organic thin films & organic/inorganic hybrid structures
ROCAM 2009, Brasov, Romania, Abstract Book xiv-xv
25-28.08.2009
6.
Antohe S, Enculescu I, Ion L
Photovoltaic cells based on organic thin films & organic/inorganic hybrid structures
Workshop on Trend in Nanoscience: Theory, Experiment, Technology, Sibiu, Sibiu, Romania,
Abstracts&Program, pgs. 18-19
23-30.08.2009
7.
Badica P, Jakob G, Beleanu A, Ksenofontov V, Felser C
Magnetic measurements under pressure of the non-centrosymmetric superconductor Li2Pd3B
synthesized by a semiopen method
DPG Spring Meeting, Dresden, Germany
22-27.03 2009, Talk
8.
Badica P, Jakob G
A facile semi-open method for synthesis of Li2(Pd, Pt)3B non centrosymmetric superconducting
bulks and thin films
9th International Conference on Materials and Mechanisms of Superconductivity (M2S),
Tokyo, Japan
7-12.09.2009, Poster
9.
Badica P, Craciunescu T, Aldica G, Tiseanu I, Jakob G, Rindfleisch M
Characterization of MgB2 by cone-beam micro-tomography
9th European Conference on Applied Superconductivity, EUCAS 2009, Dresden, Germany,
108
September
13-17.09.2009, Poster
10. Baibarac M, Baltog I, Lefrant S, Gomez-Romero S
Optical and electrochemical properties of the composites based on poly diphenylamine and single
walled carbon nanotubes
International Conference on Carbon Nanostructured Materials (Cnano'09), Greece
04-08.10.2009, Poster
11. Baltog I, Baibarac M, Lefrant S, Mevellec JY
Raman spectroscopic evidence for interfacial interactions in poly(3, 4-ethylene
dioxythiophene)/single-walled carbon nanotubes composites
04-08.10.2009, Poster
12. Baltog I, Baibarac M, Lefran St, Gautier N
Raman studies on zinc oxide/carbon nanotubes composites
04 -08.10.2009, Poster
13. Banciu MG, Nedelcu L, Ioachim A, Toacsan MI, Szilagyi A
Compact microwave antennas using advanced dielectric materials
The 6th International Edition of Romanian Conference on Advanced Materials, ROCAM 2009,
Brasov, Romania
25-28.08.2009, Talk
14. Banciu MG
Metamaterialele-dincolo de conventional
Sesiunea de comunicari a Comitetului Român pentru Istoria şi Filosofia Ştiinţei şi Tehnicii
(CRIFST) al Academiei Române din 23 octombrie 2009, desfasurată în Amfiteatrul Heliade
Rădulescu al Bibliotecii Academiei Române.
23.10.2009, Talk
15. Barvinschi F, Stanculescu A, Stanculescu F
Heat transfer process during the crystallization of benzil grown by Bridgman-Stockbarger
method
ROCAM 2009, Brasov, Romania
25-28.08.2009, Poster
16. Beica T, Frunza S, Zgura I, Ganea P, Frunza L, Zaharia CN
Complex systems as sensors for antigen-antibody reaction: nanostructureD systems based on gold
layers Deposited onto polystirene
Romanian Conference on Advanced Materials ROCAM 2009, Brasov, Romania
24-28.08.2009, Talk
17. Beica T, Zgura I, Frunza L, Andrei I, Dicu M, Pascu ML
Superficial tension of drug solutions
Joint Conference of the 7th Management Committee Meeting and Working Groups Meeting
under COST P21 Action, Bucharest, Romania
04– 06.05.2009, Poster
109
18. Beica T, Zgura I, Frunza L, Nistor LC, Morosanu C
Wettability properties of textile materials by water droplets optically visualized
04– 06.05.2009, Poster
19. Beica T, Frunza L, Zgura I, Nistor LC, Amariutei V, Dorogan A, Carpus E
Colorimetric characterization of the behavior of thermochromic dye composites I mprinted onto
fabrics
2nd International Conference Technical Textiles (Tex Tech II), Bucharest, Romania
07 - 08.05.2009, Poster
20. Beica T, Frunza S, Zgura I, Frunza L, Rasoga O, Baibarac M, Cotarlan C, Negrila CC, Vlaicu
M, Dinescu M, Zaharia CN
Sisteme nanostructurate ce contin straturi de aur depuse pe polistiren
Seminarul National de Nanostiinta si nanotehnologie, Academia Romana, Bucuresti
27.04.2009, Poster
21. Beica T, Zgura I, Frunza S, Ganea P, Firu E, Neagu AT, Haiduc M
Fotometrarea digitala a unor trase nanometrice din emulsiile nucleare
Seminarul National de Nanostiinta si nanotehnologie, Academia Romana, Bucuresti
27.04.2009, Poster
22. Beica T, Frunza S, Moldovan R, Zgura I, Dinescu AM
Metoda, celula si montaj de masura, pentru detrminarea birefringentei optice a cristalelor lichide,
in functie de temperatura
Salonul International al Cercetarii, Inovarii si Inventicii PROINVENT, Cluj Napoca
24 - 27.03.2009
23. Beleanu A, Ksenofontov V, Badica P, Jakob G, Felser C
Substitution effects on superconducting properties of Na(Ca)AlSi
DPG Spring Meeting, Dresden, Germany
22-27.03.2009, Poster
24. Berbecaru C, Nedelcu L
Dielectric properties and phase transitions of Ba0. 6Sr0. 4TiO3 ferroelectric ceramics
26-30.06.2008, Poster
25. Berbecaru C, Nedelcu L, Alexandru HV, Ioachim A, Toacsan MI, Scarisoreanu N
Synthesis and characterization of thin BZT films for microwave applications
Interdisciplinary Transport Phenomena VI: Fluid, Thermal, Biological, Materials and Space
Sciences, Volterra, Italy
4-9.10.2009, Talk
26. Bibicu I, Samide A
Mössbauer study of the tin electrodeposition
International Conference on the Applications of the Mössbauer Effect (ICAME2009),
Vienna, Austria
19-24.07.2009, Poster
110
27. Bibicu I
A detector for surface studies by Mössbauer Spectroscopy
1st International Workshop “Innovation and Evolution by R&D – SMEs Strategic
Partnership” Bucharest, Romania,
10-12.09.2009, Poster
28. Bibicu I
Studii de suprafata prin spectroscopie Mössbauer
Editia a IV-a Simpozion Stiintific Agir: Progresul Tehnologic-Rezultat al
Cercetarii, Bucuresti, Romania
10.04.2009, Talk
29. Bogdan D, Varlam C, Galatanu A, Manolachi M, Valsangiacom C, Enculescu I, Galca AC,
Valeanu M, Popescu B, Birsan A
Physical properties in RE-(Fe, Ni)4Sb12 nanostructurated skutterudites
10th International Balkan Workshop on Applied Physics, IBWAP 09, Constanta, Romania
6-8.07.2009, Poster
30. Brás AR, Frunza S, Fonseca IM, Corma A, Frunza L, Dionísio M, Schönhals A
Surface effects on the molecular dynamics of a nematic liquid crystal confined to Molecular
Sieves
6th International Discussion Meeting on Relaxations in Complex Systems, Rome, Italy
30- 05.09.2009, Poster
31. Crisan AD
Influence of glass-forming element on the structure, microstrain and thermal behaviour of
amorphous FePtNbB ribbons
International Workshop on Structural and Mechanical Properties of Metallic Glasses, IWMG09
Barcelona, Spain
17-19.06.2009, Poster
32. Crisan O, Gupta A, Reddy VR, Kuncser V, Filoti G
Exchange spring effects in FePt/Fe(Co)57Fe multilayers
International Conference on Applications of Mossbauer Effect ICAME 2009, Vienna, Austria
26-30.07.2009, Poster
33. Crisan O
Magnetic nanoclusters synthesized by a new gas stabilized aggregation technique
XXV Panhellenic Conference on Solid State Physics and Materials Science, Thessaloniki, Greece
20-23.09.2009, Talk
34. Crisan O
Aspects of corrosion in FePt-based melt spun amorphous alloys
International Workshop on Structural and Mechanical Properties of Metallic Glasses, IWMG09
Barcelona, Spain
17-19.06.2009, Poster
35. Enculescu I, Matei E, Sima M, Enculescu M, Ion L, Antohe S, Neumann R
Single bath electrodeposition of CdTe nanowire diodes
215th ECS Meeting 2009, San Francisco, SUA
24-29.05.2009, Poster
111
36. Endo K, Badica P, Yanagawa Y, Ohtsuka R, Kikuchi Y, Kezuka H, Nanto H
Thin films of the insulating (001) CaCuO2 infinite-layer with low roughness and highly uniform
morphology
19th Symposium of MRS-J, Yokohama, Japan
7-9.12.2009, Poster
37. Endo K, Badica P
Growth of HTS and other multicomponent oxide thin films and heterostructures for electronics
19th Symposium of MRS-J, Yokohama, Japan
7-9.12.2009, Talk
38. Filoti G, Palade P, Bartolome J, Valsangiacom C, Kuncser V, Mandru I, Patron L
Effect of ligands, valence and transitional ion nature on magnetic properties of hetero
oxalates
International Conference on Applications of Mossbauer Spectroscopy (ICAME), Vienna,
Austria
26-30.07.2009, Talk
39. Florica C, Mitran T, Nemnes A, Ion L, Enculescu I, Antohe VA, Radu A, Chisulescu G, Antohe S
Dye sensitized solar cells based on TiO2 nanostructures
ROCAM 2009, Brasov, Romania, pg. 66
25-28.08.2009
40. Florica C, Mitran T, Besleaga C, Tazlaoanu C, Ion L, Enculescu I, Antohe VA, Radu A, Radu M,
Chisulescu G, Antohe S
Production and characterization of Cu/Au/CdTe(ws)/CdTe/ZnPc/ZnO hybrid photovoltaic
cells
ROCAM 2009, Brasov, Romania, pg. 80
25-28.08.2009
41. Florica C, Mitran T, Nemnes A, Ion L, Enculescu I, Antohe VA, Radu A, Chisulescu G, Antohe S
Production and characterization of hybrid photovoltaic cells based on CdTe nanowire arrays and
organic dyes thin films
Annual Scientific Conference, Faculty of Physics, Bucharest, pg. 169
5.06.2009
42. Florica C, Mitran T, Besleaga C, Tazlaoanu C, Ion L, Enculescu I, Antohe VA, Radu A, Radu M,
Chisulescu G, Antohe S
Defects inducted by proton irradiation in AIIBIV thin filmsused in photovoltaic applications
International Balkan Workshop on Applied Physics, Constanta, Romania
7-9.07.2009
43. Frunza L, Frunza S, Frick B, Zorn R, Schönhals A
Dielectric and neutron spectroscopy on liquid crystals confined to nanopores 6th International
Discussion Meeting on Relaxations in Complex Systems, Rome, Italy
30- 05.09.2009, Poster
44. Frunza L, Frunza S, Kosslick H, Schönhals A
Local order in the surface layer of some thermotropic liquid crystals confined to molecular sieves
Deutsche Zeolith-Tagung, , Kiel, Germany
04 -06.03.2009, Poster
112
45. Frunza L, Gheorghe N, Ganea P, Frunza S, Kosslik H, Eckelt R
Horseradish peroxidase hosted in molecular sieves: surface interactions and oxidation activity
Deutsche Zeolith-Tagung, Kiel, Germany
04 -06.03.2009, Poster
46. Frunza L, Gheorghe N, Iova F, Ganea P, Neatu F, Parvulescu VI
Spectroscopic characterization of some layered materials of LDH- type. Analysis of the interstitial
anions
Sesiunea Stiintifica Anuala a Facultatii de Fizica, Universitatea Bucuresti, Magurele
06 -08.06.2009, Talk
47. Galatanu A, Manolachi M
Electron and phonon engineering routes for improoved thermoelectrical properties of rareearths based materials
6-8.07.2009, Poster
48. Galca AC, Secu M, Vlad AA, Pedarning JD
Optical and structural properties of AZO thin films obtained by PLD,
6-8.07.2009, Poster
49. Gartner M, Anastasescu M, Predoana L, Barau A, Teodorescu VS, Zaharescu M
Comparative study of thermal crystallization and pulsed laser annealing of high-k sol-gel HfO2
thin films
9th International Symposium on Crystallization in Glasses and Liquids, Iguasu FallsBrazil 1013.09.2009, Talk
50. Gartner M, Anastasescu C, Anastasescu M, Teodorescu VS, Zaharescu M
SiO2 nanospheres and tubes obtained by sol-gel method
The XII International Conference on the Physics of Non-Crystalline Solids (PNCS XII), Foz do
Iguaçu, PR, Brazil
6-13.09.2009, Talk
51. Gartner M, Stoica M, Nicolescu M, Teodorescu VS, Buiu O, Predoana L, Zaharescu M
UV-VIS-NIR & IR spectroscopic ellipsometry applied to the characterization of HfO2 sol-gel
thin films
5th Workshop Ellipsometry, Zweibruecken, Germany
2-4.03.2009, Talk
52. Ghica C, Nistor LC, Ghica D, Stefan M, Mironov B, Dinescu M, Vizireanu S, Dinescu G
Laser treatment of plasma hydrogenated silicon wafers
E-MRS, Strasbourg, France
8-12.06.2009, Poster
53. Ghica C, Nistor LC, Kuncser VE, Schinteie G, Epurescu G, Dinescu M, Ion L, Antohe S, Velisa G,
Ionescu P, Scintee N, Pantelica D, Grob JJ, G. Van Tendeloo
TEM characterization of ferromagnetic Co-implanted ZnO films
E-MRS, Strasbourg, France
8-12.06.2009, Talk
113
54. Ghica C, Nistor LC, Kuncser VE, Schinteie G, Epurescu G, Dinescu M, Ion L, Antohe S, Velisa G,
Ionescu P, Scintee N, Pantelica D, Grob JJ, G. Van Tendeloo
TEM characterization of ferromagnetic Co-implanted ZnO films
Joint IFIN-HH, ICTP, IAEA Workshop on Trends in nanoscience: theory, experiment,
technology, Sibiu, Romania
23-30.08.2009, Talk
55. Ghica C, Nistor LC, Ghica D, Stefan M, Mironov B, Dinescu M, Vizireanu S, Dinescu G
Laser treatment of plasma hydrogenated silicon wafers
Joint IFIN-HH, ICTP, IAEA Workshop on Trends in nanoscience: theory, experiment,
technology, Sibiu, Romania
23-30.08.2009, Poster
56. Girtan M, Vlad A, Mardare D, Stanculescu A
Pulsed laser deposited aluminium doped zinc oxide films on PET substrates
E-MRS 2009, Strasbourg, France
08 -12.06.2009, Talk
57. Girtan M, Stanculescu A, Rasoga O, Pattier B, Sylla M, Monteil A
Sol-gel deposited in: ZnO films for solar cells applications
25-28.08.2009, Poster
58. Grecu MN, Grecu VV, Giurgiu LM, Gabor MS, Petrisor T
EPR on LCMO and LSMO thin films manganites
2nd International Meeting on Materials for Electronic Applications (IMMEA-2009)
Hammamet, Tunisia
08.05-10.05.2009, Talk
59. Grecu MN, Constantinescu S, Chinie AM, Georgescu S, Pascuta P, Culea E
Clustering of rare earth ions in oxide glasses: EPR, Mössbauer and optical spectroscopy
studies
International Conference of the Applications of Mössbauer Effect (ICAME2009)
20.07-24.07.2009, Poster
60. Grecu MN, Constantinescu S, Grecu VV, Olar R, Badea M
EPR and 57Fe-NGR investigations of some tris(8-hydroxyquinoline) metal compounds
International Conference of the Applications of Mössbauer Effect (ICAME2009)
20.07-24.07.2009, Poster
61. Grecu VV, Grecu NM, Georgescu S
EPR evidence of local disorder in solids
2nd International Meeting on Materials for Electronic Applications, IMMEA-2009,
Hammamet, Tunisia
08.05-10.05.2009, Talk
62. Grecu VV, Grecu NM, Tarabasanu D
EPR studies of some oxidic diluted magnetic semiconductors
10th international Balkan Workshop on Applied Physics (IBWAP2009) Constanta, Romania
06.07-08.07.2009, Talk
114
63. Hrib LM, Dascalu G, Dumitru I, Feder M, Diamandescu L, Caltun OF
Cobalt ferrite and barium titanate composites
IEEE ROMSC 2009 (6th edition), Iasi, Romania
6-9.06.2009, Poster
64. Hrib LM, Dascalu G, Palamaru NP, Iordan AR, Slatineanu T, Dumitru I, Feder M, Caltun OF
Magnetostriction coefficients on manganese substituted cobalt ferrite obtained by
autocombustion methods
PhD Students Workshop on Fundamental and Applied Research in Physics, Univ. Al. I. Cuza,
Iasi, Romania
24.10.2009, Poster
65. Ion L, Enculescu I, Matei E, Tazlaoanu C, Radu A, Antohe S
Electrical and photoelectrical properties of heterojunction based on CdTe nanowire array and
oganic des flms
2nd International Symposium on Flexible Organic Electronics, Porto Carras Grand Resort,
Halkidiki, Greece, pg.110
8-10.07.2009
66. Ivan I, Miu L, Popa S, Miu D, Mele P, Matsumoto K
Comparison of the critical current density of YBCO films obtained by dc sputtering and pulsed
laser deposition
25-28.08.2009, Poster
67. Jinga S, Andronescu E, Jinga C, Ioachim A, Nedelcu L, Banciu MG
Synthesis, microstructure and microwave dielectric properties of Ba(Mg1/3Ta2/3)O3 ceramics
9th International Balcan Workshop on Applied Physics, IBWAP 2009, Constanta, Romania
06-08.07.2009, Poster
68. Jinga S, Andronescu E, Jinga C, Ioachim A, Nedelcu L, Banciu MG
Synthesis, Microstructure and microwave dielectric properties of pure and doped
Ba(Mg1/3Ta2/3)O3 ceramics
Brasov, Romania
25-28.08.2009, Poster
69. Katuwal T, Sandu V, Almasan CC, Maple BM
Anomalous in-plane dissipation in strongly underdoped Y1-xPrx Ba2Cu3O7-δ single
crystals
International Conference on Frontiers of Physics (ICFP 2009), Kathmandu, Nepal,
2-5.06.2009, Talk
70. Kuncser V
Easy axis distribution and spin configuration
Workshop on Trends in Nanoscience: Theory, Experiment, Technology, Sibiu, Romania
23-30.08.2009, Talk
71. Kuncser V, Palade P, Schinteie G, Filoti G
Insight temperature dependent distributions of hyperfine parameters in Mossbauer Spectroscopy“
115
Austria
26-30.07.2009, Poster
72. Lazarescu MF, Toader AM, Volanschi E, Santos E, Jones H, Götz G, Bäuerle P, Lazarescu V,
Scurtu R
Surface states- and field effects at thiolate-covered GaAs(110) electrodes
5th Kurt Schwabe Symposium 2009, Erlangen, Germany
24-28.05.2009, Poster
73. Lazarescu V, Scurtu R, Lazarescu MF, Toader AM, Volanschi E
Passivation effects of 4, 4’ thio-bis-benzene-thiolate adsorbed layers on semiconducting electrodes
60th Annual Meeting of the International Society of Electrochemistry (ISE), Beijing (China)
16-22.08.2009, Poster
74. Lazarescu V, Scurtu R, Lazarescu MF, Toader AM, Volanschi E, Santos E
SHG- and EIS-investigations on thiolate-covered GaAs(110) electrodes
Journees d’Electrochimie 2009, Sinaia (Romania)
6-10.07.2009, Poster
75. Lucaci M, Tsakiris V, Valeanu M,
Shape memory NiTiCu materials used in actuation systems
International Scientific Conference, EE&AE 2009, Rousse, Bulgaria
1-3.10.2009, Poster
76. Manolachi M, Popescu B, Galca AC, Vlaicu M, Enculescu I, Birsan A, Valeanu M, Galatanu A,
Tran VH, Bauer E
Superconductivity in bulk, single crystals and thin films Mo3Sb7
6-8.07.2009, Poster
77. Matei E, Enculescu I, Ion L, Antohe S, Trautmann C, Granville S, Ansermet JP
Galvanomagnetic properties of electrodeposited semiconductor nanowires
215th ECS Meeting 2009, San Francisco, SUA
24-29.05.2009, Poster
78. Mihai IA, Banciu MG, Ioachim A, Militaru N, Lojewski G, Petrescu T
Left-handed structures for microwave applications
06-08.07.2009, Poster
79. Mihalache V, Oral A, Dede M, Miu L
Bean-Lingviston surface barrier for flux penetration in Bi2Sr2CaCu2O8+δ single crystals near the
transition temperature
25-28.08.2009, Poster
80. Militaru N, Banciu MG, Lojewski G
Design of microwave bandpass filters with cross coupling, using electromagnetic field simulation
and linear circuit optimization
06-08.07.2009, Poster
116
81. Miu L, Ivan I, Badica P, Jakob G, Miu D, Mele P, Matsumoto K, Mukaida M, Yoshida Y, Horide
T, Ichinose A, Horii S
Magnetization relaxation in YBCO films with improved supercurrent transport properties
European Conference on Applied Superconductivity (EUCAS 2009), Dresden, Germany
13-17.09.2009, Talk
82. Miu L, Ivan I, Badica P, Jakob G, Miu D, Mele P, Matsumoto K, Mukaida M, Yoshida Y, Horide
T, Ichinose A, Horii S
Origin of the fast magnetization relaxation in HTS with strong pinning
International Simposium of Superconductivity (ISS2009), Tsukuba, Japonia
1-4.11.2009, Poster
83. Nedelcu L, Ioachim A, Toacsan MI, Banciu MG, Ghetu D, Stoica G, Jinga S, Andronescu E
The effect of sintering temperature on the microwave dielectric properties of Ba(Mg1/3Ta2/3)O3
ceramics
Brasov, Romania
25-28.08.2009, Poster
84. Negrila CC, Ungureanu F, Ghita RV
Aspects of temperature dependence on Au-Ti/GaAs(SI) Schottky barrier
International Semiconductor Conference, Sinaia, Romania
12-14.10.2009, Poster
85. Nistor SV, Stefan M, Nistor LC, Mateescu CD
Localization of Mn2+ impurity ions in cubic ZnS quantum dots
Joint IFIN-HH-ICTP-IAEA Workshop on “Trends in Nanoscience: theory, experiment,
technology”, Sibiu, Romania
23-30.08.2009, Talk
86. Palade P, Vlaicu M, Ardelean O, Filoti G
57
Fe Mossbauer study of TiCr(VFe) hydrogen storage alloys
Austria
26 - 30.07.2009, Poster
87. Pana O, Aldea N, Turcu R, Macavei S, Soran ML, Teodorescu C M, Chauvet O
Characterization of the core-shell nanoparticles by using X-ray techniques
ECNP-Paris 2009 International Conference on Nanostructured and Functional Polymer-based
Materials and Nanocomposites, Paris, France
15-17.04.2009, Talk
88. Pascu ML, Andrei IR, Ticos C, Nastasa V, Beica T
Laser beams interactions with microdroplets
04– 06.05.2009, Talk
89. Plugaru R, Artigas M, Plugaru N
First principles study of oxygen vacancy induced magnetic moments in TiO2
117
8 – 12.06.2009, Poster
90. Polosan S, Secu M
X-ray excited luminescence and photoluminescence of Bi4(GeO4)3 glass-ceramics
The 7th International Conference on Luminescent Detectors and Transformers of Ionizing
Radiation LUMDETR Krakow POLAND
12-17.07.2009, Poster
91. Polosan S, Galca AC, Secu M
Bi4Ge3O12 glass scintillators - ellipsometry and spectroscopy
The 5th International Symposium on Laser, Scintilator and Non-Linear Optical Materials
ISLNOM-7, Pisa ITALY
03-05.09.2009, Poster
92. Preda S, Anastasescu C, Teodorescu VS, Zaharescu M
Sol-Gel precursor influence on titanate-based nanotubes
XV International Sol-Gel Conference «SOL-GEL 2009»", Porto de Galinhas, Brazilia,
23-27.08.2009, Poster
93. Preda S, Rusu A, Teodorescu VS, Zaharescu M
Alkali-thermal treatment for obtaining titanate nanotubes
9th International Symposium on Crystallization in Glasses and Liquids (Crystallization 2009),
Foz do Iguaçu, PR, Brazil
6-13.09.2009, Poster.
94. Preda S, Teodorescu VS, Rusu A, Zaharescu M
Precursors Influence on Titanate-Based Nanotubes Structure and Morphology
COST 539 Action – ELENA, Aveiro, Portugal
28-30.10.2009, Poster
95. Preda S, Anastasescu C, Teodorescu VS, Zaharescu M
Hydrothermally prepared titanate nanotubes, their catalytic properties and the effect of biofunctionalization
Hybrid Materials 2009, First International Conference on Multifunctional, Hybrid and
Nanomaterials, Tours, France
15-19.03.2009, Poster
96. Sahoo B, Keune W, Borca C, Januosch M, Kuncser V, Rohlsberger R
Fe K-Edge EXAFS and 57Fe Mossbauer effect investigation of antiferromagnetic FeF2 powder
Austria
26 - 30.07.2009, Poster
97. Samide A, Bibicu I, Ciuciu A, Oprea B, Oprea C
The characterization of some polymeric compounds layers formed on the surface of 316l
stainless steel used for ortopaedic implant appications
International Conference on the Applications of the Mössbauer Effect (ICAME2009)
Vienna, Austria
19-24.07.2009, Poster
118
98. Sandu V, Popa S, Plapcianu C, Sandu E, Hurduc N, Nor I
Physical properties of manganite-polysiloxanes composites obtained by co-precipitation
International Conference on Advanced Materials and Nanotechnology (AMN-4), Dunedin,
New Zealand
8–12.02.2009, Poster
99. Schinteie G, Bica D, Vekas L, Kuncser V, Palade P, Filoti G
Controlling magnetic relaxations of ferrofluids via surfactants and dispersing liquids International
Conference on Applications of Mossbauer Spectroscopy (ICAME), Vienna, Austria
26-30.07.2009, Poster
100. Scurtu R, Lăzărescu MF, Lăzărescu V
Surface states- and field-effects at bare and thiolate covered GaAs(111)A electrodes
60th Annual Meeting of the International Society of Electrochemistry (ISE), Beijing, China
16-22.08.2009, Poster
101. Socol M, Socol G, Preda N, Rasoga O, Stanculescu F, Stanculescu A
MAPLE preparation and characterization of benzil thin films
25-28.08.2009, Poster
102. Somma F, Montereali RM, Vincenti A, Polosan S, Secu M
Crystal growth and optical characterization of Pb, Tl doped LiF crystals for photonics
applications
The 5th International Symposium on Laser, Scintilator and Non-Linear Optical Materials
ISLNOM-7, Pisa ITALY
03-05.09.2009, Talk
103. Sorescu M, Diamandescu L, Tomescu A
Mechanochemical synthesis of novel sensor materials
MRS Fall Meeting, Boston USA
30.11-01.12.2009, Talk.
104. Stan GE, Pasuk I, Berbecaru C, Alexandru, Marcov DA, Ianculescu A
Bioglass thin films deposited by magnetron sputtering and their bioactivity investigated in the
simulated body fluids
10th International Balkan Workshop on Applied Physics (IBWAP), Constanta, Romania
6–8.07.2009
105. Stanculescu A, Socol M, Albu AM, Rasoga O, Stanculescu F, Ionita I, Enculescu I
Investigations of the correlation between the preparation method and the properties of anilinic
derivative functionalised polymer thin films for non-linear optical applications
International Materials Symposium, Materiais 2009, Lisbon, Portugal
05-08.04.2009, Poster
106. Stanculescu A, Albu AM, Socol G, Stanculescu F, Socol M, Preda N, Rasoga O, Girtan M, Iulian I
Thin films of maleimidic derivatives monomers for photonics prepared by MAPLE
08-12.06.2009, Poster
107. Stanculescu A, Socol M, Rasoga O, Stanculescu F, Socol G, Nistor M, Girtan M, Sylla M, Albu AM
Transport properties in organic heterostructures for transparent optoelectronics
119
08-12.06.2009, Poster
108. Stanculescu A, Stanculescu F, Socol M, Rasoga O, Girtan M
Properties of the heterostructures based on nucleic acids bases thin films prepared by vacuum
evaporation
25-28.08.2009, Poster
109. Stanculescu A
Investigation of the properties of irradiated benzil crystals
25 - 28.08.2009, Poster
110. Stanculescu F, Stanculescu A, Girtan M, Socol M, Rasoga O
Polymer doped with aniline derivatives monomers composite Films for optoelectronic
applications
25-28.08.2009, Poster
111. Stavarache I, Lepadatu AM, Stoica TF, Stan G, Marcov D, Slav A, Teodorescu VS, Teodorescu
CM, Vlaicu AM, Pasuk I, Lazanu S, Iordache G, Ciurea ML
Structural investigations of Ge dots embedded in SiO2
Romanian Conference on Advanced Materials, ROCAM 2009, Brasov, Romania
25-28.08.2009, Talk
112. Stefan M, Nistor SV, Goovaerts E
Determination of the Mn2+ ions localization in ZnS nanocristals from multifrequency ESR
investigations
8th National Seminar of Nanoscience and Nanotechnology, Bucharest, Romania
27.04.2009, Poster
113. Taouri A, Derbal H, Mountasser R, Girtan M, Stanculescu A, Sylla M
Two-photon absorbtion cross-section maesurement by thermal lens and nolinear transmission
methods: a comparative study
25-28.08.2009, Poster
114. Toacsan MI, Nedelcu L, Ioachim A, Banciu MG, Mihut L, Ganea P, Jinga S, Andronescu S,
Stoica G
Correlation of structural and dielectric properties with vibrational modes in BaMg1/3Ta2/3O3
ceramics
06-08.07.2009, Poster
115. Toader AM, Lăzărescu M, Lăzărescu V, Volanschi E
L'électrochimie de l'hémine sur des électrodes de GaAs fonctionnalisées avec 4,
4thiobisbenzènethiol
Journees d’Electrochimie 2009, Sinaia, Romania
6-10.07.2009, Poster
120
116. Teodorescu CM
Basic aspects of magnetism in two-dimensional Heisenberg, Stoner and RKKY systems ICTPIFIN-HH Advanced Workshop: Spin and Charge Properties of Low Dimensional Systems,
Sibiu, Romania
29.06– 4.07.2009, Talk
117. Teodorescu VS, Ghica C, Maraloiu AV, Mihaiu E, Zaharescu M, Dinescu M, Scarisoreanu N,
Udrea M, Blanchin MG
Structural investigations of laser processed ZnO sol-gel thin films
EMRS 2009, Strasbourg, France
8-12.06.2009, Poster
118. Teodorescu VS, Nistor LC, Maraloiu AV, Zaharescu M, Preda S, Blanchin MG
Nanostructure of TiO2 –based nanotubes obtained by hydrothermal treatment
EMRS 2009, Strasbourg, France
8-12.06.2009, Poster
119. Tolea M, Nita M, Aldea A
The measured phase in the Aharonov-Bohm interferometer
Workshop on "Trends in nanoscience: theory, experiment, technology", Sibiu, Romania
23-30.08.2009, Poster
120. Wagner FE, Palade P, Friedl J, Filoti G, Wang N
197
Au Mossbauer study of gold selenide, AuSe
Austria
26 - 30.07.2009, Poster
121
Invited Lectures
INVITED LECTURES
1. Aldea A
Quantum transport in mesoscopic systems: interference and correlation effects in quantum dots
Berliner Oberseminar-Langenbach Seminar at Weierstrass Institute für Angewandte Analysis und
Stochastik, Berlin (Germany)
18.10.2009
2. Badica P
’Beautiful’ unconventional approaches for superconductors and some selected materials
Invited open seminar at National Institute of Materials Science (NIMS) Tsukuba, Japan
11.09.2009
3. Ciurea ML
Electrical transport in silicon-based 0D structures. Experiment and modeling.
A XXII-a sesiune de comunicari stiintifice "Progrese in stiinta compusilor organici si
macromoleculari”, Iasi (Romania)
8.10-10.10.2009
4. Ciurea ML
Percolation phenomena in nanocrystalline silicon
Joint IFIN-HH, ICTP, IAEA Workshop on “Trends in nanoscience: theory, experiment,
technology”, Sibiu (Romania)
23.08-30.08.2009
5. Crisan O
Hybrid exchange spring magnets based on FePt
XXV Panhellenic Conference on Solid State Physics, 2009, Thessaloniki, Greece
20.09-23.09.2009
6. Filoti G
Nanopolymers for integrated optics
23-30.08.2009
7. Filoti G
Magnetic properties of iron containing coordination compounds
International Conference celebrating 50 YEARS of founding Institute of Chemistry, Chisinau,
Moldova
22.05-27.05.2009
8. Ioachim A
Microwave Properties of Paraelectric Ba1-xSrxTiO3 Materials
06-08.07.2009
9. Kuncser V
Magnetic configuration and magnetic relaxation of nanoparticles: a Mossbauer approach.
23.08-30.08.2009
122
Invited Lectures
10. Moldoveanu V
Generalised Master equation approach to mesoscopic transport
Centre de Physique Theorique, Marseille (France)
5.12.2009
11. Moldoveanu V
Coulomb drag in parallel quantum dots
Workshop on statistical physics, Universitaty Koc, Istanbul (Turkey)
25-27.07.2009
12. Nedelcu L
Dielectric Materials for Microwave and Millimeter Wave Applications
06-08.07.2009
13. Negrila C, Logofatu C, Macovei D, Enculescu I, Matei E, Kuncser V, Malaeru T, Georgescu G,
Neamtu J, Socol G, Axente E, Mihailescu IN, Mardare D, Apetrei R, Luca D, Mougin A, Ferré J,
Teodorescu CM
Actual studies on oxide diluted magnetic semiconductors in Romania
10th International Balkan Workshop on Applied Physics, Constanta (Romania)
6.07-8.07.2009
14. Nistor SV
EPR of transition ions in (nano)crystalline materials
Invited lecture at the Joint IFIN-HH-ICTP-IAEA Workshop on “Trends in Nanoscience: theory,
experiment, technology”, Sibiu, Romania
23.08-30.08.2009
15. Plugaru N
First principles study and neutron diffraction investigation of Y3Ni13B2, Y3Co13B2 and
Y3Ni10Co3B2; A comparison with related 1:5 systems
Workshop "DFT meets Solid State Chemistry" & the 8-th Tutorial "Hands-on-FPLO", MPICPfS Dresden, Germany (http://www.fplo.de/workshop/ws2009/index.html)
25.10-29.10.2009
16. Popescu M
Amorphous chalcogenides: Structural challenges
Amorphous and Nanostructured Chalcogenides ANC-4, Constanta, Romania
29.05-03.06 2009
17. Racec P
Scattering in cylindrical nanowire heterostructures
Workshop on "Trends in nanoscience: theory, experiment, technology", Sibiu (Romania)
23.08-30.08.2009
18. Sandu V, Popa S, Ivan I, Plapcianu C, Sandu E, Hurduc N, Nor I
Polymer functionalization with manganites
Proc 2nd International Conference on Smart Materials and Nanotechnology in Engineering,
Weihai, China
8.07-12.07.2009
123
Invited Lectures
19. Sandu V, Popa S, Pasuk I, Enculescu I, Nicolescu MS, Radicescu S
Nanostructured Ferrite Formation in Borosilicate Glass
The 2nd International Conference on Multi-functional Materials and Structures, Qingdao China,
9.10-12.10.2009
20. Stan GE, Berbecaru C, Alexandru HV, Marcov DA
Kinetics of the bio-glass in the simulated body fluid,
Romanian Conference on Advanced Materials ROCAM 2009, Brasov (Romania)
25.08-28.08.2009
21. Stanculescu A
Bulk and thin films organic materials for optic, electronic and optoelectronic applications:
preparation and characterization
Tutorial seminar: Optical properties of Materials and Applications Department, University
Angers, France
20.10.2009
22. Teodorescu CM, Lungu GA, Husanu AM, Gheorghe N, Macovei D
Structure, reactivity and magnetism of Sm and SmCo layers grown on Si(001) by molecular beam
epitaxy
Romanian Conference on Advanced Materials, ROCAM 2009, Brasov (Romania)
25.08-28.08.2009
23. Tolea F
Magnetic nanocomposites for permanent magnets.
23- 30.08.2009
124
Institute Seminars
INSTITUTE SEMINARS
1. Prof. Dr. Barsan N. (10.04.2009)
Institut fuer Teoretische Chemie, Eberhardt Karls Universitaet Tuebingen, Germany
Gas sensing with semiconducting metal oxide based sensors-operando insights
2. Prof. Cinteza L. O. (21.10.2009)
Univ de Medicina si Farmacie Carol Davilla, Bucuresti
Quantum dots-modern tools for advanced medicine
3. Dr. Filip L. D. (23.07.2009)
Faculty of Engineering and Physical Sciences, University Surrey, UK
Modelarea emisiei de camp si a tunelarii electronilor din nasnotuburi de carbon si structuri stratificate
4. Prof. Dr. Florea C. (10.04.2009)
ENSTA-Ecole Polytechnique, Palaiseau, France
Laseri compacti ultra-intensi
5. Prof. Gupta A. (11.11.2009)
Center Director, UGC-DAE Consortium for Scientific Research, Indore, India
In –situ study of magnetic thin films using magneto-optical Kerr effect
6. Dr. Kampling M. (23.04.2009)
SPECS GmbH, Berlin, Germany
PEEM-Photoemission Electron Microscopy
LEEM-Loe Energy Electron Microscopy
7. Lungu G. A., Gheorghe N. , Husanu M. A., Teodorescu C. M. (16.07.2009)
NIMP, Bucharest, Romania
Primele rezultate obtinute cu instalatia de epitaxie in fascicol molecular (MBE) a INCDFM
8. Moreau S. (10.02.2009)
SETAROM
Modele cinetice aplicate in analiza termogravimetrica diferentiala
9. Popescu T. (02.04.2009)
Jacobs University, Bremen, Germany
Gravitational waves from coalescing binary white dwarfs
10. Schlossmacher P. (02.04.2009)
Carl Zeiss SMT- NanoTechnology Systems Div., Oberkochen, Germany
Performantele microscopului electronic de transmisie LIBRA 200 FE, firma ZEISS
11. Dr. Spineanu F. (29.07.2009)
Head of the Research Unit of EURATOM-MECT
Fuziunea termonucleara controlata, principalul proiect al EURATOM
125
126
Patents
and Patent Requests
127
Patents and Patent Requests
PATENTS
1. Negrila C, Iuga A, Ghita R, Cernea M, Logofătu C, Manea AS, Lăzărescu MF
Method and set up for the semiconductor crystals growth process control
Patent Romania 122367 /30.04.2009
2. Kappel W, Romalo D, Codescu MM, Stancu N, Pintea J, Filoti G, Kuncser V, Valeanu MC,
Tolea F, Schinteie G
Compozite pe baza de Fe-Cu pentru magneti permanenti anizotropi si procedeu de obtinere a
acestora (in Romanian)
Patent Romania 122570/ 28.08.2009
3. Popescu M, Sava F, Lőrinczi A, Micloş S, Savastru D, Mustaţa M, Savastru R
Procedure and device for producing chalcogenide microlenses
Patent Romania 6/146/30.11.2009
4. Lazarescu MF, Ghita R, Logofatu C, Negrila C C, Manea AS
Procedeu de obtinere a structurilor de tip Schottky pe substrat GaAs (in Romanian)
Patent Romania 122793/29.01.2010
5. Lazarescu MF, Ghita R, Manea AS, Logofatu C, Negrila CC, Ungureanu F
Procedeu si dispozitiv de obtinere a policristalelor de fosfura de galiu (in Romanian)
Patent Romania 122815/26.02.2010
PATENT REQUESTS
6. Ungureanu F, Lazarescu MF, Negrila CC
Procedure for the obtaining of LaCOB compound by solid phase reaction
Patent request 2009
7. Ghica C, Nistor LC, Teodorescu VS, Vizireanu S, Scarisoreanu ND
Laser processing of hydrogen RF-plasma induced structural defects in silicon for the transfer of
single crystal layers thinner than 50 nm.
Patent request 2009
8. Teodorescu VS, Nistor LC, Ghica C, Dinescu M, Scarisoreanu ND
Method of periodic structuring of sol-gel oxide thin films by coherent pulsed laser processing
Patent request 2009
128
International Cooperation
129
INTERNATIONAL COOPERATION PROJECTS
Badica P.
Alexander von Humboldt Fellowship
Univ. Mainz, Germany
AvH ID No: RUM1126111STP, Grant No. 3-1126112
Li2(Pd1−xPtx)3B and related superconductors
2008-2010
Funding: EUR 100.000
Crisan A.
Marie Curie Excellence Grant
University of Birmingham
MEXT-06-041111
Self-assembling nanotechnology of pinning centres in superconducting films, devices and coated
conductors
2007-2011
Funding: EUR 1.600.000
Enculescu I.
SCOPES (Switzerland)
Functional Nanowires
2009 – 2011
Filoti G.
Network of Excellence FP 6
Molecular Approach to Nanomagnets and Multifunctional Materials (MAGMANet)
NMP-3-CT-2005-515767
2005-2010
Funding: EUR 145.000 ( for entire period )
Galatanu A.
ESF COST action P16 ECOM
Emergent behavior in correlated matter
2005-2009
Funding: EUR 1.500
Kuncser V.
International cooperation programme with JINR-Dubna (Russia)
Comparative investigations of magnetic colloid systems by means of muon and Mossbauer
spectroscopy
359/01.06.2007 Theme No 05-2-1040-2001/2009
2007-2009
Funding: USD 10.000 ( for entire period )
130
Lazanu S.
CERN, Geneva, Switzerland
R&D in the field of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders, with
focus on LHC and its up-grades (Development of Radiation Hard Semiconductor Devices for Very High
Luminosity Colliders) –Partners: 48 research institutes and universities from Europe and US.
Project cod: CERN RD 50
2002-2010
Nistor S. V.
COST Action P-15
Advanced paramagnetic resonance methods in molecular biophysics
2005- 2009
Pintilie I
CERN –RD50 (Partners: 48 research institutions from Europe, USA, Canada
(http://rd50.web.cern.ch/rd50/))
Radiation hard semiconductor devices for very high luminosity colliders
2001-2009
Pintilie I
FP7 European Project
Marie Curie Training Network on Particle Detectors (MC-PAD)
No.: 214560-2
Partners: CERN- European Organization for Nuclear Research (CH), DESY- Stiftung Deutsches
Elektronen-Synchrotron (DE), GSI- Gesellschaft für Schwerionenforschung mbH (DE), JSI- Jožef
Stefan Institute (SI), AGH- AGH University of Science and Technology (PL), LNF- Laboratori
Nazionali di Frascati - Istituto Nazionale di Fisica Nucleare (IT), NIKHEF- Stichting voor
Fundamenteel Onderzoek der Materie (NL), PSI- Paul Scherrer Institut (CH), UHH- University of
Hamburg (DE), EVATRONIX- Evatronix SA (PL), IFJ PAN- Instytut Fizyki Jadrowej im. Henryka
Niewodniczanskiego Polskiej Akademii Nauk (PL), MICRON- Micron Semiconductor Ltd. (UK),
Photonis- Photonis SAS Holding (F) (http://mc-pad.web.cern.ch/mc-pad/ )
2008 -2012
Predoi D.
ERASMUS
Surface properties of iron oxide nanoparticles for biomedical applications
2009-2013
Predoi D.
ERASMUS
Biogeochemistry of iron in surface environments
2009-2013
Stanculescu A.
Brancusi Romania -France Project
Organic structures on organic conductor substrate for optoelectronic and photovoltaic applica-tions
Project no. 216-2/15.04.2009
131
Teodorescu C.
Synchrotron-radiation facility HASYLAB (Hamburger Synchrotron-strahlungslabor) at DESY
(Deutsches Elektronen-Synchrotron), Hamburg, Germany
Titanium dioxide based nanomaterials and nanostructured films with applications in the
photocatalytic degradation of environmental polluting organic contaminant
Project code: II-20052058
2006-2009
Teodorescu C.
Synchrotron-radiation facility HASYLAB (Hamburger Synchrotron-strahlungslabor) at DESY
(Deutsches Elektronen-Synchrotron), Hamburg, Germany
X-ray absorption fine structure studies of Diluted Magnetic Semiconductors formed by doping ZnO
and TiO2 with transition metals: Cr, Mn, Fe, Co, Ni
Project code: II-20070135EC
2007-2010
Vasiliu F.
COST Action 540
Photocatalytic technologies and novel nanosurfaces materials -critical issues (PHONASUM)
2005-2010
Funding: EUR 30.000
132
BILATERAL COOPERATION PROJECTS (AGREEMENTS)
Aldica G.
Universitatea din California, Davis, SUA
Tomography and image analysis of dense and bioactive nanocrystalline hydroxyapatite obtained by
rapid sintering under the influence of external electrical fields
2007-2009
Aldica G.
Universita degli Studi di Torino, Italy
Synthesis of nanostructured superconducting materials by means of unconventional techniques
2008-2010
Baltog I.
Institute des Materiaux Jean Rouxel, Nantes, France
Composites and hybrids materials based on conjugated polymers and carbon nanotubes studied by
Raman light scattering, FTIR spectroscopy, photoluminescence and electrochemical techniques
2003-2010
Baibarac M.
Materials Science Institute, Barcelona, Spain
Hybrid materials based on conducting organic polymers (COP) and semiconducting and metallic
nanoparticles synthesis, characterization and applications.
2005-2009
Ciurea M. L.
Cankaya University, Ankara, Turkey
Modelling and simulation: transport phenomena in nanostructures (0D, 1D and 2D)
2008 – 2013
Funding: EUR 10000
Ciurea M. L.
Middle East Technical University, Ankara, Turkey
Quantum dot solar cells
2008 – 2011
Ciurea M. L.
Optics and Plasma Research Department Risø National Laboratory Technical University of
Denmark – DTU, Roskilde, Denmark
Nanostructured materials
2007-2010
Constantinescu S.
Institute Francilien of Geosciences, University of Marne la Vallée, France
Natural semiconductors (arsenopyrite and tourmaline) and gold ores/ mineralization, the crystallochemistry investigation of arsenopyrit minerals (structural association, defects and traps of gold) from
South Carpathians deposits (Valea Stan, Costesti Jidostita)
2006-2009
133
Crisan A.
Nanoelectronics Research Institute of AIST Tsukuba, Japan
Comprehensive Agreement on Joint Scientific Cooperation in the field of Science and Technology of
Advanced Materials
2007-2012
Crisan O.
Programme Hubert Curien PHC “ Brancusi”:ANCS – CNRS
Laboratoire de Physique de l’Etat Condense, UMR CNRS 6087, Universite du Maine, Le Mans,
France
Hard magnetic nanocrystalline materials obtained from amorphous precursors
2008-2010
Funding: USD 20.000 (for entire period)
Crisan O.
UGC-DAE Consortium for Scientific Research, Indore, India
New magnetic low dimensional systems
2007-2009
Funding: USD 15.000 ( for entire period)
Diamandescu L.
Duquesne University, Physics Department, Pittsburgh, USA
Solvothermal elaboration and the study of physical properties of some substituted oxide structures
2006-2010
Frunza L.
Institute of Physics of National Academy of Sciences of Ukraine (IOP), Kiev, Ukraine
Physical bases of the structure forming and phase transitions in heterogeneous systems such as
inorganic nanoparticles in organic matrix (liquid crystals, polymers etc)
2009-2011
Frunza L.
Leibniz-Institut fűr Katalyse e.V. an der Universität Rostock, Rostock, Germany (LIK)
Surface effects in complex nanostructured systems with potential applications in catalysis
2009-2011
Galatanu A.
Univ. of Nantes, Institute of Materials , Nantes, France
Physics of strongly correlated electron systems in Kondo insulators, localization phenomena and
applications
2006-2011
Kuncser V.
University of Duisburg, Germany
Interphase mechanisms in thin layer compounds and composites
2007-2012
134
Kuncser V.
JINR-Dubna, Russia
Comparative investigations of magnetic colloid systems by means of muon and Mossbauer spectroscopy
Project code 359/01.06.2007 Theme No 05-2-1040-2001/2009 with JINR-Dubna
2007-2009
Funding: 10.000 USD for entire period
Miu L.
Institute of Physics, University of Mainz, Germany
Vortex dynamics in HTS films and superlattices
2008-2011
Miu L.
Department of Materials Science and Engineering, Kyushu Institute of Technology, Japan
Magnetization relaxation in HTS films with improved supercurrent transport properties
2008-2011
Moldoveanu V.
Physics Division, Science Institute, University of Iceland, Iceland
Non-linear and time-dependent transport in mesoscopic systems: theory and applications to
semiconductor spintronics
2008-2011
Moldoveanu V.
Physics Department, Faculty of Physics, Bilkent University, Turkey
Quantum coherence and charging effects in mesoscopic spin filters
2009-2011
Morosanu C.
Department of Ceramic and Glass Engineering, University of Aveiro, Portugal
Preparation, structural characterization and in vitro evaluation of implant-type bio-glass thin films
deposited onto titanium alloy substrates
2008 - 2010
Funding: EUR 4500
Morosanu C.
Department of Materials Science and Engineering, University of Ioannina, Greece
Development and evaluation of bioactive multilayer implants from ceramic coated titanium for tissue
engineering applications
2007 - 2009
Funding: EUR 3600
Nistor L. C.
University of Antwerpen, EMAT Laboratory Antwerp, Belgium
Nano-structured multifunctional oxide materials: the role of the local structure on their physical and
chemical properties
2005-2009
135
Nistor S. V.
University of Antwerpen, ECMP Laboartory, Antwerp, Belgium
Designing new advanced, multifunctional materials with lattice defects
2005-2009
Popescu M.
University of Marakesh, Morocco
Materials and methods for detection of pollutants in water
2008-2010
Funding: EUR 10000
Popescu-Pogrion N.
Instituto de Ceramica y Vidrio, Madrid, Spain
Advanced materials for alternative energies and clean environment
2007 – 2010
Popescu-Pogrion N.
Sabanci University, Istanbul, Turkey
2007 – 2011
Popescu-Pogrion N.
The Institute of Advanced Manufacturing Technology (IOS), Krakow, Poland
2007 – 2010
Popescu-Pogrion N.
International Science & Technology Centre, Russia
Project code: ISTC A-1695 Transparent Conductive Nanomaterials for Solar Cell
Nanotubes / Diamond Like Carbon Composite Transparent Conductive Material for Solar Cell and
Conductive Coating Applications
2009 – 2012
Predoi D.
Le Havre University France
Ultrasonic characterization of bio-ceramics powders and fero-fluids
2007-2012
Predoi D.
University of Bordeaux I, France
Magnesium based nanocomposites for hydrogen storage and Fe oxide colloids
2005-2012
Sandu V.
JINR-Dubna, Russia
Investigation of controlled recrystallization in glasses containing d3 elements
Project code 15/24.11.2008 Theme No 04-4-1069-2009/2011 with JINR-Dubna
2009-2011
136
Stanculescu A.
University of Angers: Optical Properties of Materials and Applications (POMA) Laboratory,
France
Organic and hybrid compounds. Low dimension organic multilayer structures
2008-2011
Stoica T.
Institute fuer Bio-und Nanosysteme , Juelich, Germany
Physical measurements on GaN, InN and SiGe
2007 - 2009
Teodorescu V. S.
University “Claude Bernard”, LPMCN., Lyon, France
Systemes nanoparticulaires polymers/oxides en vue d’applications biomedicales
2007-2009
Tomescu A.
Institut für Physikalische und Theoretische Chemie, University Tuebingen, Germany
Complex investigations of p-type semiconducting metal oxides; potential applications
2008 - 2009
Funding: EUR 24400
137

laboratory of advanced materials for special applications

Transcription

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