Book of abstracts - RACIRI Summer School 2016

Transcription

RACIRI Summer school 2013:
"Advanced Materials Design at X-ray and Neutron
Facilities: Soft Matter and Nano Composites"
Book of Abstract
17–25 June
Saint-Petersburg
2013
Dr. Natalia Grigoryeva
Saint-Petersburg State University
Faculty of Physics
Saint-Petersburg, 198504, Russia
The RACIRI summer school strives for strengthening the scientific knowledge base
of young researchers in advanced materials design with a strong connection to
the excellent research infrastructures in the region and to contribute to the
necessary interdisciplinary literacy in relevant scientific fields and disciplines.
The RACIRI summer school is a joint initiative by Sweden, Russia and Germany
embedded in the collaborative frameworks of the Röntgen-Angström-Cluster
(RAC) and the Ioffe-Röntgen-Institute (IRI).
Partnering organizing institutions are NRC Kurchatov Institute in Russia, DESY in
Germany and the Swedish Research Council Vetenskapsradet.
RACIRI Summer school 2013: "Advanced Materials Design at X-ray and Neutron
Facilities: Soft Matter and Nano Composites":
Book of Abstract / Ed. N. Grigoryeva — Saint-Petersburg, publishing house
"SOLO", 2013. — 98 p.p. with illustrations.
ISBN 978-5-98340-315-4
RACIRI Summer school 2013
Organizers
Saint-Petersburg State University, Faculty of Physics
National Research Centre "Kurchatov Institute"
B.P. Konstantinov Petersburg Nuclear Physics Institute
Objectives
It is an important element towards a vivid Baltic science and innovation area to
harness the potential of the next generation of researchers and to fully exploit the rich
scientific infrastructure in the future.
The program structure, lectures and topics of the RACIRI summer school are designed
to improve the fundamental understanding in advanced materials design rather than
focusing on plain experimental methods and techniques. This will enable young
researchers to better tackle today’s and tomorrow’s challenges and key barriers in
materials sciences.
Location
The first RACIRI summer schol take place in the Hotel New Peterhof in the municipal
town Petergof (Russian: Петерго́ф) or Peterhof (Dutch/German for "Peter's Court") in
the district of St. Petersburg, located on the southern shore of the Gulf of Finland.
The town hosts one of two campuses of Saint Petersburg State University. A series of
palaces and gardens, laid out on the orders of Peter the Great, and sometimes called
the "Russian Versailles", is also situated there. The palace-ensemble along with the city
center is recognized as a UNESCO World Heritage Site.
3
Committee
Steering Committee:
Helmut Dosch, Chairman of the Board of Directors at DESY
Mikhail Kovalchuk, Director NRC “Kurchatov Institute”
Ulf Karlsson, Head of the Swedish Delegation and Coordinator RAC, KTH Stockholm
Scientific Committee:
Russia:
Serguei Molodtsov (European XFEL and current chair of scientific commitee),
Alexander Ioffe (FZJ)
Germany:
ndreas Stierle (DESY),
Klaus Habicht (HZB)
Sweden:
Jens Birch (Linköping University),
Aleksander Matic (Chalmers U).
Local Organization Committee:
Kashkarov P.K. NRC “Kurchatov Institute”
Rychev M.V. NRC “Kurchatov Institute” / European XFEL
Altynbaev A.V. NRC “Kurchatov Institute”
Yatsyshina E.B. NRC “Kurchatov Institute”
Grigoryeva N.A. Saint-Petersburg State University
Spitsyn A.V. NRC “Kurchatov Institute”
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RACIRI Summer School-Program
Saturday, 17 August 2013
10.00–19.00
Arrival and Check in (New Peterhof Hotel, Russia, 198510, St.
Petersburg, Peterhof, St. Peterburgsky Prospect, 34, Tel. + 7 (812)
319-10-10)
19.00–23.00
Welcome dinner with barbecue and beer
Sunday, 18 August 2013
12.00–13.00
Lunch
13.00–13.30
Welcome:
Helmut Dosch, Chairman of the Board of Directors of DESY
Mikhail Kovalchuk, Director of NRC Kurchatov Institute
Ulf Karlsson, Coordinator of RAC, KTH Stockholm
Serguei Molodtsov (European XFEL and chair of RACIRI scientific
commitee)
Mikhail Rychev (European XFEL, NRC Kurchatov Institute)
13.30–14.20
Introductory lecture:
Mikhail Kovalchuk, NRC Kurchatov Institute (RU)
"Convergence of sciences and technologies: from inanimate tо living
matter"
14.20–14.40
Coffee Break
Photon Sources: Facilities, technics and scientific basics
14.40–15.30
L1: Massimo Altarelli, European XFEL (DE)
"From 3rd to 4th Generation Sources: X-Ray Experiments with FreeElectron Lasers"
15.30–16.20
F1: Richard Neutze, Gothenborg University (SE)
"Structural and dynamical studies of proteins at an X-ray free electron
laser"
5
16.20–16.40
Coffee Break
Neutron Sources: Facilities, technics and scientific basics
16.40–17.30
L2: Victor Aksenov, PNPI Gatchina (RU)
"Reactor neutron sources"
17.30 –18.20
F2: Ken Andersen, ESS (SE)
"Pulsed neutron sources"
19.00–20.30
Dinner
20.30–22.00
Free Time
Monday, 19 August 2013
Theory 1 (real structure related)
08.00–09.30
L3: Igor Erukhimovich, Lomonosov U Moscow (RU)
"Polymer nanostructures in the bulk and under nanoconfinement:
physics, scattering, applications
Summer School Cultural Programme
Peterhof Garden
09.30–13.00
13.00–14.00
Lunch
14.00–15.30
F3: Efim Kats, Landau Institute and ILL (RU/F)
"Determination of structural and physical features of colloidal
systems from small angle scattering data"
15.30–16.00
Coffee Break
Theory 2 (electronic structure related)
16.00–17.30
L4: Alexander Lichtenstein, U Hamburg (DE)
"Advanced methods in electonics structure calculations"
17.30–18.00
Coffee Break
18.00–19.30
F4: Hans Agren, KTH Stockholm (SE)
"DFT calculations of X-ray spectra"
19.30–20.30
Dinner
20.30–22.00
Poster session
Tuesday, 20 August 2013
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Diffraction 1 (atomic: single crystals, powders)
08.30–10.00
L5: Jens Als-Nielsen, Riso National Laboratory (DK)
"X-rays and Neutron-Fundamentals in 90 minutes"
10.00–10.30
Coffee Break
10.30–12.00
F5: Christian Riekel, ESRF (F)
"Aspects of Functional Biomaterials"
12.00–13.30
Lunch
Diffraction 2 (molecular: single molecules, polymers, colloids, etc.)
13.30–15.00
L6: Sunil Sinha, U San Diego (USA)
“X-ray and Neutron scattering from surfaces of complex fluids”
15.00–15.30
Coffee Break
15.30–17.00
F6: Sergei Chvalun, NRC Kurchatov Institute (RU)
“Nanostructured polymeric and hybrid materials synthesized by VDPprocess: Electronic and optoelectronic application”
19.00–20.30
Dinner
20.30–22.00
“What is…?”
Wednesday, 21 August 2013
FREE DAY
08.30–13.00
Facility Tour Gatchina
13.00–14.00
Lunch
14.00–21.30
21.30–22.30
Dinner
Thursday, 22 August 2013
Imaging 1 (solid matter, domains and membranes)
08.30–10.00
L7: Carolyn Larabell, LBNL (USA)
“Imaging biological specimens with X-rays”
10.00–10.30
Coffee Break
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10.30–12.00
F7: Chris Jacobsen, APS/ANL/Northwestern U (USA)
“X-ray microscopy: combining imaging and spectroscopy”
12.00–13.30
Lunch
Imaging 2 (large molecules, clusters, gels and liquids)
13.30–15.00
L8: Michael Avdeev, JINR (RU)
“Structural nanodiagnostics of ferrocolloidal systems by neutron
scattering”
15.00–15.30
Coffee Break
15.30–17.00
F8: Joachim Dzubiella, HU Berlin, HZB (DE)
“Theory and modeling of structural aspects and dynamics of liquids”
19.00–20.30
Dinner
20.30–22.00
Key note lecture:
Paul Chaikin, New York University (USA)
"Artificial Life"
Friday, 23 August 2013
Spectroscopy 1 (electronic structure related)
08.30–10.00
L9: Joachim Stöhr, SLAC (USA)
“Investigation of Nanoscale Dynamics in Materials with an X-Ray
Laser”
10.00–10.30
Coffee Break
10.30–12.00
F9: Emad Flear Aziz Bekhit, HZB (DE)
“Structure and dynamics of biochemical systems in solution using
modern soft X-ray spectroscopy and table-top techniques“
12.00–13.30
Lunch
Spectroscopy 2 (real structure related)
13.30–15.00
L10: Michael Monkenbusch, FZJ (DE)
“Dynamics of Macromolecules”
15.00–15.30
Coffee Break
15.30–17.00
F10: Natalia Novikova, Inst. of Crystallography RAS (RU)
“X-ray fluorescence methods for investigations of lipid/protein
membrane models”
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19.00–20.30
Dinner
20.30–22.00
Paper presentations
Saturday, 24 August 2013
Materials Preparation 1 (crystal growth, epitaxial films, self-assembling, etc.)
08.30–10.00
L11: Alexander Vul‘, Ioffe Institute (RU)
“Preparation and characterization of the new carbon nanostructures:
nanodiamonds, carbon onions and graphenes”
10.00–10.20
Coffee Break
10.20–11.50
F11: Frank Schreiber, Uni Tübingen (DE)
“Growth processes and their characterisation by X-rays and neutrons”
11.50–13.00
Lunch
Materials Preparation 2 (biosamples, wet chemistry, gels, etc.)
13.00–14.30
L12: Michael Mertig, Uni Dresden (DE)
“Biomimetic material synthesis”
14.30–14.50
Coffee Break
14.50–16.20
F12: Dmitrii Gorin, Uni Saratov (RU)
“Core-shell nanocomposites”
16.30–24.00
And School Dinner with Awards
Sunday, 25 August 2013
10.00–12.00
Check out and Departure
9
Two aspects of my research in the field of scattering
Adlmann Franz1
1
Division of Material Physics, Department of Physics and Astronomy, Uppsala University, Sweden
[email protected]
In this poster two aspects of my research are presented.
The first part is highlighting the properties of Pluronic
F127 micelles using grazing incident neutron scattering.
The crystal structure and the average lattice constant can
be extracted analyzing the scattering pattern. By
introducing a time of flight measurement, additional
information of the ordering of the micelles in dependence
of penetration depth is derived.
In the second part the magnetic behavior of Palladium in
presence of a small layer of iron is described. A phase
retarder is inserted in the beam of synchrotron radiation
on the Palladium L3 edge. This produces an instant
change of the orientation in the circularly polarized light.
Hence it is possible to derive the magnetic anisotropy
profile and consecutively calculate the magnetic
polarization in the boundary layer. Plotting the
polarization over the dimensionless temperature, the
nature of the magnetic phase transition is revealed.
10
Magnetic structure of MnGe in a wide temperature range
E. V. Altynbayev1,2, S.-A. Siegfried3, N.M. Potapova1,
V. A. Dyadkin1,4, E. V. Moskvin1,2, D. Menzel5, Ch. Dewhurst6,
R.A. Sadykov7,8, L.N. Fomicheva8, A.V. Tsvyashchenko8,
S. V. Grigoriev1,2
1
Petersburg Nuclear Physics Institute, NRC Kurchatov Institute, Gatchina, Russia, 188300;
2
Faculty of Physics, Saint-Petersburg State University, 198504 Saint Petersburg, Russia;
3
Helmholtz Zentrum Geesthacht, 21502 Geesthacht, Germany;
4
Swiss-Norwegian Beamlines at the ESRF, Grenoble, 38000 France;
5
Technische Universität at Braunschweig, 38106 Braunschweig, Germany;
6
Institute Laue-Langevin, F-38042 Grenoble Cedex 9, France;
7
Institute for Nuclear Research, RAS, 142190, Troitsk, Moscow, Russia;
8
Institute for High Pressure Physics, 142190, Troitsk, Moscow Region, Russia.
Corresponding Author’s e-mail: [email protected]
INTRODUCTION
The cubic B20-type compound MnGe orders
below TN in a one-handed spin helical structure
with a small propagation vector k ≈ 2.2 nm-1.
The small-angle neutron scattering (SANS)
experiments are performed to study details of
the temperature evolution of the spin structure
above and below TN. It is widely recognized
that the magnetic structure of MnGe is built on
the hierarchy of interactions: the strongest
ferromagnetic exchange interaction, the
antisymmetric
Dzyaloshinskii-Moryia
interaction, and the weakest cubic anisotropy
[1, 2]. The magnetic system based on these
interactions is ordered in the long period helix.
The antisymmetric exchange interaction and
cubic anisotropy fix the orientation of spiral
along the principal axes of the cubic structure.
EXPERIMENT
Polycrystalline MnGe samples has been
synthesized by high pressure method at the
Institute for High Pressure Physics. As they can
be only sinthesized under high pressure,
samples are in a polycrystalline powder form
crystallites with size not less than a micron (see
[3] for details). The X-ray powder diffraction
confirmed the B20 structure of these samples
and showed traces of impurities less than 1-2%
in the volume fraction. Magnetic susceptibility
measurements were carried out with the
SQUID-magnetometer after cooling in zero
magnetic field to T = 5 K, then heating in the
magnetic field of 50 mT.
SANS measurements were carried out at
instrument D-11 at ILL reactor, Grenoble,
France. The scattering intensity is measured
upon zero field cooling from the paramagnetic
state at T = 300 K to the ordered state at T = 5 K
with the step of 5 K.
RESULTS
MnGe undergoes a complex transition from the
para- to helimagnetic phase. At low temperature
range the single Bragg reflection indicates a
stable helimagnetic structure of this compound.
The peak on the diffraction pattern is well
described by Gaussian function with the width
limited by the setup resolution function. With
temperature increase the influence of spin
excitations added to the scattering process. This
phenomena leads to the transformation of the
scattering profile from Gaussian into complex
function that consists of Voigt and step-like
functions what is well seen on the scattering
picture. At high temperature range the scattering
function transforms to the single Gaussian with
center value equal to zero Q. This ascribed to
Gaussian distribution of magnetic spirals with
wavevector k approaching zero.
11
REFERENCES
[1] P.Bak, M.H.Jensen, J.Phys. C13, L881
(1980).
[2] I.E. Dzyaloshinskii, Zh. Exp. Teor. Fiz. 46
1420 (1964) [Sov. Phys. JETP 19, 960 (1964)].
[3] A. Tsvyashchenko, Journal of the Less
Common Metals 99, 2, L9 (1984)
12
Structure of the Vanadium — Doped Nd5Mo3Oy Single Crystal
A.M. Antipin1, O.A. Alekseeva1, N.I. Sorokina1,
E.P. Kharitonova2, V.I. Voronkova2
1
Shubnikov Institute of Crystallography, Russian Academy of Science, Moscow, Russia,
2
Faculty of physics, M.V. Lomonosov Moscow State University, Russia
[email protected]; [email protected]
There is a compound with the fluorite-like
structure, which is formed in the oxide system
Nd2O3 — MoO3 with an oxide ratio of 5:6
(Nd5Mo3Oy). This fluorite-like structure is
formed both in a reducing atmosphere and at the
air [1–4]. This compound with a mixed
electronic-ionic conductivity [5] is of great
scientific and practical interest.
The aim of this work — a study of the structure
of Nd5Mo3Oy single crystals, doped with
vanadium, which were obtained by self-flux
method in the oxide system at the air.
The structures of two single crystals
Nd5Mo2.9V0.1Oy (I) and Nd5Mo2.76V0.24Oy (II)
were studied at the XCalibur S (Oxford
Diffraction) diffractometer with CCD detector at
the room temperature. Data collection and
processing were performed with the CrysAlis
CCD and CrysAlis RED software, respectively.
The structure has been refined by the leastsquare method, using the JANA2006 refinement
program. Crystal structure of the fluorite-like
Nd5Mo3O16 compound obtained at the reducing
atmosphere was studied for the first time in [1],
and the coexistence of molybdenum with two
valences +5 and +6 was discovered. The valence
state of the atoms was analyzed in details on the
base of neutron-diffraction study of the
isostructural Pr5Mo3O16 compound [2] and
deviations of the valences from normal state
was found for all the cations. The same
deviations were found in the single crystal
structure Nd5Mo3Oy, studied with X-rays [4]. It
should be noted that no oxygen vacancies were
found in the praseodymium compound and the
oxygen conductivity was associated with the
free oxygen in the cavities of the structure. In
[4] ionic conductivity was explained by the
observed disorder of atoms in the crystal
structure. In the present study it was shown that
the atomic displacements found in [4] for the
pure Nd5Mo3Oy compound, are kept after the
doping with vanadium and the impurity atoms
are located in the molybdenum positions.
The values of the activation energy were
calculated on the basis of structural data and the
possible migration paths of the oxygen ions
were analyzed for the structures I and II. It was
found that the O2 oxygen ions make the main
contribution to the ionic conductivity, which is
consistent with data on the occupation and
disordering of the oxygen positions.
ACKNOWLEDGMENT
This study was supported in part by the RFBR
grant №11-03-00243а, by Department of
Physical Science RAS within the Program in
Support of Fundamental Research and Leading
Scientific
Schools
(project
no.
NSh2883.2012.5).
REFERENCES
1. P. Hubert, P. Michel, A. Thozet // Seances
Acad. Sci., Ser. C. 1973. V.275. P.1779.
2. J.B.Bourdet, R.Chevalier, J.P.Fournier,
R.Kohlmuller, J.Omaly // Acta cryst. 1982.
B38. P.2371.
3. M.J. Martinez-Lope, J.A. Alonso, D.
Sheptyakov, et al. //J. of Solid State
Chemistry. 2010. V.183. P.2974.
4. O.A. Alekseeva, A.B. Gagor, A.P.
Pietraszko,et al. // Z.Kristallogr. 2012.Vol.
227. No.12. Р.869.
5. Voronkova V.I., Kharitonova E.P., Belov
D.A. // Solid State Ionics. 2012. V.225.
P.654.
13
Application of the Method of Neutron Activation Analysis for
Determination of Nanoparticles Transport Properties
in Biological Tissues in Vivo
А.А. Antsiferova¹
[email protected]
The growing use of nanoparticles in light and
food industries, pharmacology, nutritional
supplements makes us wonder about
nanoparicle’s influence onto the living
organism. It is already proven that most of the
nanoparticles are toxic for living cells and their
toxicity is higher than for macroparticles with
the same chemical and crystalline structure. The
fact is caused by their high penetrability and the
specific uptake mechanism such as endocytosis.
That’s why it is highly necessary to investigate
interaction between nanoparticles and biological
tissues. This investigation may include as their
transport and transition inside an organism as
mechanism of their interaction with living cells
and toxic effects onto biological tissues.
In the present work we have to stop at the first
problem and our initial goal is to understand the
transport properties of nanoparticles. Here we
limit the objective by investigation only the
nanoparticles of some metals and their oxides
such as silver, aurum, titanium dioxide and zinc
oxide. The choice is due to the applied
techniques.
Listed nanoparticles are administered orally and
parenterally into digestive tract of experimental
rats and mice. Further as it is supposed they
“travel” with the blood flow to tissues and
penetrate through some of their barriers
interacting with cells and after that nanoparticles
may be excreted or accumulated within tissues.
The problem is to determine kinetics of their
accumulation and excretion from main organs.
Thus, they must be somehow traced.
Chosen element compounds are able to produce
long-living isotopes under proton or neutron
radiation as a result of nuclear reaction with a
resulting photon emission. Thus, nanoparticles
of these elements may be traced by their gamma
activity. This method allows us to determine
integral characteristics as total concentration of
nanoparticles in each biological tissue and
obtain their dependencies on time.
We must distinguish chronicle, acute and sub
acute ways of administration. Among other
main data it has already been shown that silver
nanoparticles at chronicle administration tend to
accumulate within cerebrum and kidney.
Behavioral tests in mice also demonstrate
drastic changes in their behavior such as
characteristic photophobia reduction and stress
resistance increase. Aurum nanoparticles are
mostly accumulated within liver.
These results strongly connected to other main
data may lead to understanding biophysical
mechanisms of interaction between nanoparticle
and the living organism and the knowledge is
able to prevent humankind damage. Thus, still
there is a wide open field for research.
REFERENCES
[1]. Lyudmila V. Zhukovaa, John Kiwib, Vitaly V. Nikandrov, “TiO2 nanoparticles
suppress Escherichia coli cell division in the
absence of UV irradiation in acidic conditions”,
Colloids and Surfaces B: Biointerfaces 97
(2012) 240–247.
[2]. Min Tua, Yi Huanga, Hai-Ling Li, ZhongHong Gao, “The stress caused by nitrite with
titanium dioxide nanoparticles under UVA
irradiation in human keratinocyte cell ”,
Toxicology 299 (2012) 60–68.
[3]. Sandra Gissela Marquez-Ramireza, Norma
Laura Delgado-Buenrostroc, Yolanda Irasema
Chirinoc, Gisela Gutierrez Iglesias, Rebeca
Lopez-Marure, “Titanium dioxide nanoparticles
inhibit proliferation and induce morphological
changes and apoptosis in glial cells”,
Toxicology 302 (2012) 146–156.
[4]. Adriano A. Torranoa, Angela S. Pereiraa,
Osvaldo N. Oliveira Jr. b, Ana BarrosTimmons, “Probing the interaction of oppositely
14
charged gold nanoparticles with DPPG and
DPPC Langmuir monolayers as cell membrane
models”, Colloids and Surfaces B: Biointerfaces
108 (2013) 120–126.
[5]. Falck, G.C., Lindberg, H.K., Suhonen, S.,
Vippola, M., Vanhala, E., Catalan, J.,
Savolainen, K., Norppa, H.,. Genotoxic effects
of nanosized and fine TiO2. Hum. Exp. Toxicol.
28 (2009) 339–352.
15
Industrial Applications of Synchrotron Radiation
G.A. Appleby
PT-DESY, Deutsches Elektronen Synchrotron, Notkestraße 85, 22607 Hamburg, Germany
[email protected]
The unique properties of synchrotron radiation
makes it ideal for detecting chemical elements
and environments within fluids, glasses,
amorphous solids and crystalline materials
making them applicable to a wide range of
industrial fields.
At synchrotron facilities such as DESY, MAXLab and BESSY, many industrial companies
from a wide range of industrial category –from
agriculture to nanotechnology to cosmetics to
chemical companies –have had measurements
and analysis performed on their materials in
order to solve a specific problem or for general
product development.
The benefit for the company of such
measurements is that they can simply deliver
their samples to the laboratory and beamscientists perform state of the art scientific
measurements and analysis themselves. The
measurements can be scheduled much faster
than for regular academic users while the results
can be made confidential, while academic users
must publish all results.
For the synchrotron itself, the benefits include a
relatively high income (250 –750€ per hour of
beamtime) as well as involvement in applied
research which can be presented to the general
public as easy-to-understand examples of what
kind of science is being performed at these
expensive and generally not well understood
large research centres.
EXAMPLES OF INDUSTRIAL
MEASUREMENTS
In Agriculture and Food Science, analysis can
be
performed
on
trace-elements
and
contamination in soil, as well as to understand
and slow down aging processes in foods. For
Chemical companies, Understanding catalytic
reactions for new catalyst development is
possible as well as chemical and structural
characterisation of powders, colloids and
nanomaterials. In Construction and Engineering,
analysis of stress, fatigue and moisture content
in building materials can be made, and also
testing of new alloys for automobile and aircraft
components for resistance to stress, fatigue and
corrosion.
Environmental
and
Energy
companies can examine the functioning and
stability of solar panels and investigate low
energy lightning, cooling and heating devices.
For companies in Home and Personal Care, insitu investigation at temperature dependent
behaviour, stability and ageing of formulations
or ingredients can be made, as well as
monitoring of the effects of cosmetics on the
molecular structure of skin, fingernails and hair.
In Life Science and Biotechnology, drug
characterisation and the development of novel
pharmaceuticals is possible, as well as
tomography of biomechanical components. In
Material
Science
and
Nanotechnology,
Chemical and phase analysis in novel materials
can be performed as well as characterisation of
coatings and thin films.
This poster will outline the wide variety of
industrial applications of synchrotron radiation
as well as providing specific examples and case
studies of industrial measurements performed
recently at DESY, MAX-Lab and BESSY.
16
Development of the method for time resolving observation of
Rocking curves by Ultrasonic Modulation
of the Lattice Parameter
A.E. Blagov1, A.V. Targonsky1, P.A. Prosekov1, Yu. V. Pisarevsky1,
M.V. Kovalchuk 1,2
1
A.V. Shubnikov Institute of Crystallography Russian Academy of Sciences,
Leninskij prospect 59, Moscow, Russia
2
National research centre "Kurchatov institute", 1, Akademika Kurchatova pl., Moscow, 123182, Russia
E-mail: [email protected]
Development of the method for measuring
angular distribution of X-ray beam diffraction
intensity (method for measuring X-Ray rocking
curves (RC)) is represented. Intensity
distribution analysis in this method is conducted
by ultrasonic modulation of a lattice parameter
of X-ray-acoustic crystal, used as an X-ray
scheme optical element. The possibility to
conduct precise time-resolved measurements of
X-ray
rocking
curves
without
using
sophisticated goniometry system is the
distinctive feature of this method.
Special
elements
X-ray
acoustic
resonators, consisting of a piezoelectric crystal
(quartz) and X-ray optical crystal (silicone) was
developed to implement the method. These
resonators was used to create a standing acoustic
wave and effectively control a tensioncompression deformation. Developed X-ray
optical schemes allow us to create uniform timevariable deformation of crystal lattice inside Xray beam footprint.
We propose several methods of RC
measuring: 1,2 – use of X-ray acoustical
resonator as controllable monochromator (Bragg
and Laue geometry); 3,4 – application of X-ray
acoustical resonator as X-rays analyzer in Brag
and Laue position.
Rocking curves, measured by proposed Xray acoustic methods by shape and halfwidth
agrees well to curves measured according to
traditional way − by rotating a crystal.
Experimental results of method approbation examples of rocking curves of different
reflections
measured
on
laboratory
diffractometer using X-ray acoustic method will
be presented.
Experimentally achieved resolution of the
method is 0.1 arcsec. Developed method and
experimental schemes are totally applicable for
synchrotron radiation conditions.
REFERENCES
1. Blagov A.E., Kovalchuk M.V., Kohn V.G.,
Lider V.V. Pisarevsky Yu.V. JETP 2005,
128, p893
2. Blagov A.E., Kovalchuk M.V., Kohn V.G.,
Pisarevsky Yu.V. Cryst. Rep. 2006, 51 p.701
3. M. V. Kovalchuk, A. V. Targonskii, A.
E. Blagov, I. S. Zanaveskina and Yu. V.
Pisarevskii Cryst. Rep., 2011, 56, 5, p. 828−83
17
Transport properties of the La0.75Ca0.25MnO3 manganite
I.A. Bondarev1 and N.V. Volkov1,2
1Siberian Federal University, pr. Svobodny 79, Krasnoyarsk, 660041 Russia
2 Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch,
Krasnoyarsk, 660036 Russia
e-mail: [email protected]
NTRODUCTION
Manganese oxides with a perovskite structure
called manganites attract much attention with a
great variety of effects observed in these
materials,
such
as
colossal
negative
magnetoresistance, metal-insulator transition,
and high degree of spin polarization. Studies of
the magnetotransport properties of manganites
are relevant for both fundamental research and
application.
RESULTS AND DISCUSSION
Figure 1 shows the temperature dependence of
the resistance for the La0.75Ca0.25MnO3 sample
in the range 80−273 K at frequencies from 1
kHz to 2 MHz in the absence of an external
magnetic field and in the field H = 1000 Oe
applied perpendicular to the transport current
direction in the crystal.
One can see that at T ≈ 170 K there are
resistance maxima. The peaks are sharper in the
absence of an external magnetic field; in the
presence of field H, they are shifted toward
higher temperatures.
Figure 2 demonstrates the frequency
dependence of the resistivity in the range 1
kHz−2 MHz at the temperature T = 200 K.
It can be seen that with an increase in frequency
the resistivity decreases. In addition, the
frequency dependence is affected by applied
magnetic field H, especially in the lowfrequency range.
CONCLUSIONS
In this work, we presented the measured ac
temperature and frequency dependences of the
resistivity R(T) and R(ω) for the single-crystal
La0.75Ca0.25MnO3 manganite in the absence
of a magnetic field and in a field oriented
perpendicular to the direction of the transport
current in the sample.
Fig. 1. R(T) dependences in the
0 and (b) H = 100 Oe.
fields (а) H =
Fig. 2. R(ω) dependences in the fields H = 0 and
H = 10 kOe
18
Dielectric glass-ceramics for mobile applications
in the GHz frequency range
Hubertus Braun1,2,3, Martin Letz1, Hans-Joachim Elmers2,3,
Martun Hovhannisyan1,4
1
2
SCHOTT AG, Mainz (Germany),
Johannes Gutenberg-Universität Mainz, Institute of condensed matter (KOMET) (Germany),
3
Graduate School Materials Science in Mainz (MAINZ) (Germany),
4
Tech. Universität Darmstadt, Institute of microwave engineering and photonics (Germany)
[email protected]
ABSTRACT
In recent years, the continuous growth in mobile
communication technologies operating in the
microwave frequency range demands costefficient low-loss dielectric materials with
sufficiently high permittivity [1]. Conventional
microwave devices like antennas or filter
elements which operate close to lossy materials,
such as human tissue, decrease their
performance due to additional dielectric losses
(Body Loading effects). These effects can be
prevented by using Dielectric Loading.
Therefore metallised low-loss high permittivity
ceramics (εr ~ 20-80) are needed which allow a
high concentration of the EM near-field inside
the dielectric and thereby a reduction of external
influences [2]. An additional advantage of
dielectric loaded devices lies in their smaller
size compared to conventional pure metal
devices, following the miniaturization trend of
microelectronics of the last decades.
In the current work, glass-ceramics in the TiO2SiO2-B2O3-Al2O3 system are developed (εr ~
16-32, Qf ≈ 10.000GHz, |τf | < 10 ppm/K)
which have promising properties as microwave
materials and offer a number of advantages in
comparison to conventional sinter-ceramics.
One advantage lies in the possibility to balance
the τf parameter close to zero using glassy and
crystalline phases (τf: relative change of
resonance frequency with temperature).
Materials which are obtained via a true glassy
phase are relatively new in this field and are an
alternative to conventional sinter-ceramic
fabrication techniques [3]. Glass-ceramics are
produced in a two step process: At first, a
homogeneous basic glass is casted in a
conventional glass production process. Then the
basic glass undergoes a temperature treatment
with a defined temperature profile (< 1100°C) to
initiate a controlled partial crystallization of
desired paraelectric crystalline phases inside the
glassy matrix (Ceramisation). Obtaining
materials via a homogeneous glassy phase
enables intrinsic pore free materials with
comparatively superior surface properties.
Additionally the effect of solid solution type
doping on the dielectric properties and glass
stability is investigated and the glass-ceramic
materials are analyzed concerning suitability for
dielectric
loaded
antenna
applications.
Comparative measurements with antennas made
from commercially used sinter-ceramics are
made.
REFERENCES
[1]: Microwave Dielectric Ceramics for
Resonators and Filters in Mobile Phone
Networks, I. Reaney, D. Iddles, J.Am. Ceram.
Soc., 89[7]2063-2072(2006)
[2]: Circularly Polarized Dielectric-Loaded
Antennas: Current Technologies and Future
Challenges, M. Mirsaneh, O. Leisten, B.
Zalinska, I. Reaney, Adv. Funct. Mat. 2008, 18,
1-8
[3]: Bismuth Niobate Glass-ceramics for
Dielectrically Loaded Microwave Antennas, M.
Mirsaneh, O. Leisten, B. Zalinska, I. Reaney,
Appl. of Ferroelectrics, 2008, ISAF 2008, vol.2
19
Porosity Characterization of UHMWPE-derived Materials for
Medical Application
Iu.Bykova 1, V.Altapova 1,3, S.Lebedev 1, T.Baumbach 2,3,
I.Khlusov 1,4 and V.F. Pichugin 1
1
National Research Tomsk Polytechnic University, Lenin Ave. 30, 634050 Tomsk, Russia, 2 Institute for Photon Science and Synchrotron
Radiation, KIT, 76344 Eggenstein-Leopoldshafen, Germany, 3 Laboratory for Applications of Synchrotron Radiation, KIT, 76128
Karlsruhe, Germany, 4 Siberian State Medical University, Moscow Tract 2,634050 Tomsk, Russia
[email protected]
OBJECTIVE
The present work contains the characterization
and X-ray examination of UHMWPE
materials in terms of their application in
orthopedics as polymer compounds of
endoprostheses for total joint arthroplasties.
The possibility of 3D imaging of internal and
surface geometry of weakly absorbing porous
UHMWPE using synchrotron radiation phase
contrast based on diffraction grating
interferometer is shown. Obtained 3D images
allow analyzing the structural properties of the
materials: porosity, pores size, and a level of
their interconnectivity.
INTRODUCTION
Nowadays a key component of tissue
engineering approach to tissue regeneration is
a concept of production of natural or artificial
material that acts as a template for cells
providing structural support and guiding them
to the newly formed tissue [1]. To fit these
functions it must have an appropriate porosity,
adequate surface area and a definite threedimensional shape. Ultra-High Molecular
Weight Polyethylene (UHMWPE) is actively
used material for fabrication of sliding element
in biomedical application. Macro- and
micropores as the defects of UHMWPE
internal structure decrease its mechanical
properties
and
increase
failure
rate
dramatically. So, nondestructive control of
polymer compounds before and after
implantation is a state of art for a prognosis of
prosthesis fate. Nowadays X-ray phasecontrast imaging is established and
successfully
developed
technique
for
biomedical nondestructive 3D visualization of
weak-absorbing materials. X-ray phasecontrast imaging provides qualitative and
quantitative information about scaffold
structure in term of pore size and pore
interconnectivity, also monitoring of tissue
ingrowth [2]. In combination with grating
interferometry (GI) it helps to achieve high
phase sensitivity in a case of low detector
resolution.
MATERIALS AND METHODS
The samples of UHMWPE and its copolymers
were used in the present work. Experimental
UHMWPE samples were produced by
compression moulding technique. UHMWPE
powder at the mould was pressed at a
controlled rate (15 kN), and temperature
170C was applied to the mould using electric
heated system. For fabrication of samples with
a porous structure powder UHMWPE
GUR4022 (Ticona LLC) were used. An
average particle size is 120-150 µm, the
density of the polymer is around 55 g/cm3. The
formed polymers and copolymers possessed
both porous and dense internal structure. The
materials had a shape of round or rectangular
plates with the thickness around 0.8-1 mm,
that were divided into square samples of 1×1
cm2 size.
It is known that phase contrast imaging
enhances the contrast for the fine features
within a sample. To achieve the high phase
sensitivity a grating interferometry setup was
applied [3]. The main elements of grating
interferometer are phase-shift grating G1 and
absorption grating G2. As a rule phase-shifting
grating is made of not absorbing material
20
which splits an incoming wave into diffraction
orders. Because of interference of diffracted
beams it is possible to observe the intensity
variation of wave field and self-imaging effect
(Talbot effect). Self-images of grating occur
on the Talbot distance that can be written as:
p
dn  n 1 ,
2
where n – the Talbot order, and p = p1
effective period of resulting diffraction pattern
for  phase-shift grating. For detection the
2
diffraction pattern introduced after phase-shift
grating the detector with very high resolution
is needed. To avoid the limitation of used
detector an absorption grating G2 with the
same period as the diffraction pattern (p = p2)
can be used. Absorption grating is made out of
a highly absorbing material with high atomic
number that works as a mask for detector.
After G2 propagation transferred slow
oscillating Moire fringes are easily identified
by low resolution detector [4].
Figure 1. Schematic view of a grating
interferometer setup.
Computed laminography (CL) measurements
were done at the Topo-Tomo beamline at
ANKA, Karlsruhe Institute of Technology,
Germany. A detector system included CCD
camera PCO 4000 with an effective pixel size
of 2.5 µm and field of view of 10×6.7 mm2.
For the CL data the angle 30 degrees was
chosen. For each measurement series 2500
projection images were taken over an angular
range of 360° with exposure time 20ms for one
projection and scan duration was 3 hours.
Darkfield (camera-specific artifacts) and
flatfield (beam and gratings-related artifacts)
images were taken to reduce an artifact
formation during reconstruction.
Investigation of the 3D scaffold structure leads
to further information about the volume
features of materials. Images, obtained using
x-ray grating interferometry CL, are displayed
in figure 2 (a)–(c). It shows the results, i.e., the
absorption (a), phase gradient (b), dark-field
(c). Three different signals are monitored
during one measurement (absorption, phase,
and small angle scattering) is an undoubted
advantage of the phase contrast method. The
images show that pores have a rounded form
with the average size around 100 µm that
corresponds to the results from optical
microscopy. The proposed scaffolds have
shown to present a pore distribution in the
range of the optimal pore sizes. The pores are
interconnected and look like the agglomerates
of smaller units.
Figure 2. Images of porous UHMWPE
obtained using grating interferometer a)
absorption b) phase-contrast c) dark-field.
For the evaluation of 3D pore distribution the
image processing software MAVI-Modular
Algorithms for Volume Images was
implemented. For 3D calculation the sample
size 660×660×660 µm3 were chosen. 90% of
all amount of pores are interconnected, that
mean the low presence of isolated pore units,
which makes them more similar to the organic
cartilage or bone tissue.
21
Figure 3. Pore size distribution for 3D image
of
UHMWPE
(90
%UHMWPE
(GUR4022)+10 %PVDF).
The diameter of pores varies from 28 to 245
µm. Pore size distribution for 3D image
showed that internal structure of porous
scaffolds may be suitable for tissue
engineering. Porous sample (GUR4022)+10
%PVDF) has an average diameter of pores
between 60-90 µm (33%), around 21% of the
pores has a diameter distribution 90-120 µm,
14% of pores are bigger than 120 µm. For
example, it is considered as the sufficient pore
size for implants integration with bone tissue
[5]. Around 32% of pore sizes are lower than
60 µm. The porosity level is around 15 % of
scaffold volume. Stem cells and other types of
cells (chondroblasts, osteoblasts, etc) have real
possibility to populate porous structure of
tested samples. At the same time, natural
cartilage has a porosity varying from 68 % to
85 % in adult joints. The pore size <100 µm
and low porosity may potentially limit an
access of nutrients to cells. On the other hand,
decreasing the pore size improves the retention
of the synthesized molecules of intercellular
matrix [6].
CONCLUSION
Synchrotron radiation is a powerful technique
for polymeric biomaterials investigation. The
image analysis obtained by grating
interferometry in laminographic geometry
allows
non-invasive
and
accurate
quantification of three-dimensional structure
of biomaterials, helps to evaluate pore size,
pore
distribution, their
volume
and
interconnectivity. The obtained CL GI-based
3D images of polymer has a resulting voxel
size 5,5 µm ×5,5 µm ×5,5 µm.
It is a positive achievement to develop X-ray
phase microtomography for non-destructive
testing
of
polymer
compounds
of
endoprostheses for total joint arthroplasties ex
vivo and in vivo. On the other hand, it may be
applied to select weakly absorbing porous
biomaterials with optimal porosity for tissue
bioengineering. A level of microtopography
(porosity, roughness) has to play a
determinative role in a control of cell behavior
on the surface and in pores of material.
Moreover, achieved geometry resolution (2030 µm) allows hoping to visualize cells
seeding and colonization in the bulk
microterritories of polymer scaffold ex vivo
and step by step in vivo.
REFERENCES
1 W.L. Graysona, et al (2009) Biomimetic
approach to tissue engineering. Seminars in
Cell & Developmental Biology 20:665–673.
2 R. Cancedda, et al (2007) Bulk and interface
investigations of scaffolds and tissueengineered bones by X-ray microtomography
and X-ray microdiffraction. Biomaterials
28:2505–2524.
3 V. Altapova, et al (2011) X-ray phasecontrast radiography using a filtered white
beam with a grating interferometer. Nuclear
Instruments and Methods in Physics Research
Section A: Accelerators, Spectrometers,
Detectors
and
Associated
Equipment
648:S42-S45.
4 M. Żenkiewicz (2007) Methods for the
calculation of surface free energy of solids.
Journal of Achievements in Materials and
Manufacturing Engineering 24.
5 J. S. Capes et al (2005) Fabrication of
polymeric scaffolds with a controlled
distribution of pores. Journal of materials
science: materials in medicine 16:1069 – 1075.
6 S.Grad, et al (2004) Scaffolds for Cartilage
Tissue Engineering: Effect of Pore Size.
European Cells and Materials 7:1–3.
22
Structure and self-organizationin magnetic liquids
Hauke Carstensen, Max Wolff, Vassilios Kapaklis
Material physics, Department of Physics and Astronomy, Uppsala University
[email protected]
INTRODUCTION AND APPROACH
Ferrofluids are magnetic liquids that contain
nanometer sized magnetite particles. They are
commercially used in many different
applications, e.g. in high-end loudspeakers or as
liquid seals. Furthermore ferrofluids are object
of present research.
We present a new route of addressing selforganization in a magnetic liquid. The basic idea
behind it is that ferrofluid is used as solvent for
micrometer
sized
ferromagnetic
and
diamagnetic particles. The effective magnetic
behavior of the particles is altered since they
replace ferrofluid in a certain volume. This
effect can be seen analogue to the Archimedes
principle.
The approach described above makes it possible
to tune the magnetic properties of the
micrometer sized particles by changing the
concentration of nanometer sized particles in the
solvent and thus the effective magnetic behavior
of the large particles. Due to the magnetic
interaction, the larger particles arrange
themselves in lattices. By changing the
ferrofluid
concentration
the
magnetic
susceptibility of the solvent is changed and the
effective susceptibility of the larger particles is
altered. Therefore the interaction between them
is tunable and different structural arrangements
can be created.
We have studied the phase transition from cubic
to hexagonal ordering while continuously
increasing the magnetic susceptibility of the
solvent. The positions of the particles were
visualized by particle specific dyes and the use
of an optical microscope. The individual particle
positions were evaluated automatically and a
model to quantitatively explain the results is
presented.
OUTLOOK: NEUTRON SCATTERING
While 2D systems can be observed by light
microscopy, this is not possible for 3D systems.
These systems can be analyzed by neutron
scattering. Small angle scattering can provide
the correlation function between the particles
and therefore the structure in which the particles
are ordered.
Neutron scattering provides high contrast, since
the colloid is water-based and can easily be
deuterated to achieve high contrast.
Additionally polarized neutrons can be used to
investigate in the magnetic properties.
Numerical simulation of the system provides a
model of the structure, in which the particles are
arranged. This can be used to improve the fitting
of the scattering results.
23
Comparative morphology of macromolecules of
Immunoglobulin-M and human Rheumatoid Factor
from SAXS data
Deniza I. Chekrygina1, Vladimir V. Volkov1, Victor A. Lapuk2,
Elena Yu. Varlamova3
1
Institute of Crystallography, Russian Academy of Sciences, 117333 Leninsky pr. 59, Moscow, Russia.
Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Leninsky pr. 47, Moscow, Russia
3
Hematology Research Center, Russian Academy of Medical Sciences, 125167 Novozykovsky proezd, 4a,
Moscow, Russia [email protected]
2
STATEMENT OF PURPOSE
Due to the wide spread of human immune
diseases comprehensive investigations of the
morphology
of
macromolecules
of
immunoglobulins and human rheumatoid factors
are of high importance. Despite of the fact that
atomic [1] and low-resolution structural models
[2] of these macromolecules were obtained
previously, the problem of structural and
functional differences between these two kinds
of immunnoglobulins are still unrevealed. The
main purpose of this work was in the
determination of structural models of
immunoglobulin-M
(IgM)
and
human
rheumatoid factor (IgM-RF) from small-angle
X-ray scattering (SAXS) data and clarifying the
difference between shapes of the proteins.
INTRODUCTION
IgM
and
IgM-RF
are
the
biggest
macromolecules among immunoglobulins. Up
to now there is no reliable model of IgM-RF,
and its structural difference from IgM is still not
clear. Large molecular masses (about 900-1000
kDa) and high flexibility of the proteins make
their crystallization impossible. One of the most
important questions in immunology is the
difference between structures of IgM and IgMRF. In particular, it is crucial to know lowresolution shapes of IgM and IgM-RF. One of
the
best
nondestructive
methods
of
determination
of
shape
models
of
macromolecules in solution is the small-angle
X-ray scattering (SAXS). Earlier studies [2]
suggested that the differences between IgM and
IgM-RF should be in the peripheral Fab regions,
because they contain the antigen-binding sites
responsible for the antibody function. Analysis
of SAXS data in [2] allowed authors to conclude
that the difference is explained by higher
asymmetry of Fab-RF pairs, and, probably, by
lower molecular mass of the entire IgM-RF. In
the present work, the comparative structural
study of IgM and IgM-RF was performed on the
large set of SAXS data (previous and novel) to
provide more details.
APPROACH
Small-angle X-ray scattering was applied to
study structural characteristics of the
immunoglobulins. Experiments were done at the
beamline X33 (DESY, EMBL c/o Hamburg).
SAXS data processing was performed using
ATSAS program package [4] and original
software.
The maximum diameters and radii of gyration
were obtained using pair distribution functions
calculated by the regularized Fourier transform
program GNOM [4].
Low-resolution molecular shapes were obtained
by two ab initio methods, DAMMIN [4], which
employing a dummy atom (bead) model of a
particle, and GASBOR [4] employing a chainlike ensemble of dummy residues. The
programs fit experimental scattering intensity by
a global minimization method based on
simulated annealing and random search of
spatial arrangement of the structural elements.
The program DAMPRIS was developed to
calculate radial distributions as a relative
number of dummy atoms depending on their
distance from the center of the model.
24
Samples of the human monoclonal IgM and the
rheumatoid factor IgM-RF (Waldenström’s
disease) were prepared according to the
procedures [3] with concentrations from 2.3 to
12.5 mg/ml.
The maximum diameters (Dmax) of IgM and
IgMRF and radii of gyration (Rg) were
estimated from pair distribution functions.
According to the results, in the case of IgM
samples Dmax was found to be 39-41 nm and Rg
of about 12.4–12.8, while in the case of the
IgM–RF the values were evaluated as 36-38 nm
and Rg =10.8–11.6 nm. The typical models
obtained are shown in the Figure.
10 nm
Figure. Typical structure models of IgM-RF obtained from SAXS data using spherical dummy atoms by
DAMMIN (a-d), model using amino-acid residues by GASBOR (e) and Perkins atomic model (PDB:
2RCJ) [1] of IgM.
For all structural models radial distribution
functions were calculated using about 100
simulations obtained from 5 series of samples.
Comparison of the radial distributions
confirmed the conclusion about lower density
and looseness of the peripheral regions of IgMRF versus intact IgM macromolecules.
REFERENCES
1. Perkins S.J., Nealis A.S., Sutton B.J.,
Feinstein A. Solution Structure of Human and
Mouse Immunoglobulin M by Synchrotron Xray Scattering and Molecular Graphics
Modelling. A Possible Mechanism for
Complement Activation. // J. Mol. Biol. 1991.
V.221. P.1345.
2.Volkov V.V., Lapuk V.A., Kayushina R.L.,
Shtykova E.V., Varlamova E.Yu., Malfois M.
and Svergun D.I. Low-resolution structure of
immunoglobulins IgG1, IgM and rheumatoid
factor IgM-RF from solution X-ray scattering
data. // J.Appl.Cryst. 2003. V.36. P.503–508.
3. V. A. Lapuk, A. I. Chukhrova, E. V.
Chernokhvostova, V. A. Aleshkin, G. P.
German, E. Yu. Varlamova, A. M. Ponomareva,
N. P. Arbatskii, and A. O. Zheltova. A simple
25
method
for
isolation
of
monoclonal
immunoglobulin M with rheumatoid activity. //
Biochemistry (Moscow). 1992. V.57.P.617–626.
4. Konarev P.V., Petoukhov M.V., Volkov
V.V., Svergun D.I. ATSAS 2.1, a program
package for small-angle scattering data analysis.
// J. Appl. Crystallogr. 2006. V.39, P.277–286
26
Surface modification of metal oxide nanoparticles through
controlled radical polymerization for improving electrical
insulation in HVDC cables
Carmen Cobo Sánchez, Martin Wåhlander, Linda Fogelström,
Anna Carlmark, Ulf Gedde, Eva Malmström1
1
KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of
Fibre and Polymer Technology, SE–100 44 Stockholm, Sweden
Corresponding author: Carmen Cobo Sánchez, [email protected]
Energy consumption increases daily in the
world. This fact implies that new ways to
produce and/or transport energy must be
investigated. The development of new
environmentally friendly energy sources from
different parts of the globe will involve the
creation of improved insulation cables to
transport this energy efficiently. Following this
path, new advanced materials must be
developed. One of the suggested approaches is
to include inorganic nanoparticles in the
crosslinked polyethylene (XLPE) matrix used
for high voltage direct current (HVDC) cables.
These nanoparticles are intended to change the
charge distributions in the matrix, reducing the
possible treeing of the material, which is one of
the most common defects. However, a perfect
interface contact between nanoparticles and
matrix is desired. Inorganic nanoparticles have a
hydrophilic surface, whilst polyethylenes and
other cable material are mostly hydrophobic.
Due to this, surface modification of
nanoparticles is often needed.
In this study, three different types of inorganic
nanoparticles, zinc oxide (ZnO), aluminum
oxide (Al2O3) and magnesium oxide (MgO) are
modified through surface initiated atom transfer
radical polymerization (SI-ATRP).
In a first step, organic initiating-containing
compounds, such as silanes, phosphonic acid,
dopamine and disulfide compounds are attached
to the surface of the nanoparticle by covalent
bonding. This addition enables the ATRP of
different monomers from the nanoparticle
surface. In this work, methyl methacrylate
(MMA), 2-ethylhexyl acrylate (EHA) and lauryl
methacrylate (LMA) are polymerized from the
nanoparticles and characterized to corroborate
the success of this modification. It can be seen
that the degree of grafting of the nanoparticles
depends on the type of nanoparticle and the
quantity of organic compound added.
Nevertheless, surface initiated polymerizations
can be correlated between the different materials
and the polymer itself, showing a potentially
controlled system. Characterization is carried
out through SEC, NMR, SEM, FT-IR, TGA and
DLS.
In a second step, the grafted nanoparticles will
be added to a polyethylene matrix and the
corresponding materials will be characterized
mechanically and electrically.
RACIRI Summer
school 2013
Figure 1. Scheme of the grafting of an Al2O3 nanoparticle
with poly(methyl
methacrylate) initiated with a phosphonic acid.
27
Saxs Derived 3d-Model Of The Novel Bacterial Fructose
1,6-Bisphosphate Aldolase
L.A. Dadinova1, E.V. Rodina2, N.N. Vorobieba2, E.V. Shtykova1
1
2
A.V.Shubnikov Institute of Crystallography, RAS, Leninsky pr., 59, 119333, Moscow, Russia;
Lomonosov Moscow State University, Chemistry Department, Leninskie gory, 1, Bldg. 3, 119991,
Moscow, Russia
Fructose-1,6-bisphosphate aldolases (Fba) are
cytoplasmic enzymes, which play a crucial role
in metabolic regulation [1]. Among different
forms of aldolases, bacterial Fba (FbaB) is
considered to be a new family of the enzymes.
Up to now neither 3D structure nor the spatial
quaternary organization of FbaB were
determined. However, it is well known that
interaction of FbaB with the essential cell
enzyme, inorganic pyrophosphatase (PPase)
leads to significant physiological consequences
[2]. Thus, to analyze structural characteristics of
the novel bacterial FbaB and of its complex with
PPase in solution, using small-angle X-ray
scattering (SAXS) and advance SAXS data
interpretation methods, is an actual and
important task.
The results of the shape reconstruction of the
individual FbaB and PPase macromolecules are
shown in Fig. 1 (a & b). Bottom inserts in
Figure 1 demonstrate low resolution shapes of
the enzymes restored by the program
a
lg I, relative
p(r) 18
16
14
12
10
8
6
4
2
0
4
3
0
4
6
8
10
12
r, nm
2
1
2
3
1
0.0
0.5
1.0
1.5
s, nm-1
b
lg I, relative
APPROACHES
SAXS data were collected at the beamline P12
(DESY, Hamburg). Data processing was
performed using ATSAS program package [3].
Low-resolution shapes of the specimens were
reconstructed by ab initio method (program
DAMMIN) employing annealing protocol and a
dummy atom (bead) model of a particle. To run
the program and to determine the maximum
sizes (Dmax) of the scattering objects, distance
distribution function p(r) was computed by
indirect Fourier transformation and program
GNOM. Method of molecular tectonics (rigid
body modeling and program SASREF) was also
applied to characterize the mutual arrangement
of the enzyme macromolecules in the complex.
To evaluate the amount of FbaB-PPase
complexes formed in solution program
OLIGOMER was used.
2
p(r) 25
4
20
15
10
5
3
0
0
2
4
6
8
r, nm
2
1
2
3
1
0.0
0.5
1.0
1.5
2.0
2.5
s, nm-1
Figure1.
DAMMIN and GNOM model curves, as it is
clearly seen from Fig. 1 (a, b), yield good fits
(curves 2 & 3, respectively) to the experimental
data (curves 1) with average discrepancy 0.5.
Estimated from p(r) functions (top inserts in
Fig. 1) maximum sizes of FbaB and PPase were
28
found to be 12.4 nm and 7.8 nm,
correspondingly.
Further step of our study was reconstruction of
low resolution shape of FbaB-PPase complex in
solution. We used two approaches: ab initio
protocol and rigid body modeling. Both
approaches yield reconstructions of the same
shapes and sizes revealing elongate body with
the size of 20.3 nm. The results are shown in
Fig. 2. Figure notations are analogous to those
in Fig. 1.
lg I, relative
p(r) 18
16
14
12
10
8
6
4
2
0
4
3
0
5
10
15
20
r, nm
2
1
2
3
1
0.0
0.5
1.0
the complex, while other part exists in solution
as
individual
particles.
Such
partial
complexation can be explained by the fact that
even though contacts between subunits in both
proteins are very tight, the proteins can
dissociate in solution [2].
CONCLUSIONS
During our investigation we for the first time
have analyzed low resolution organization of
novel bacterial FbaB emzyme, macromolecular
parameters of which were unknown up to now.
Moreover, for the first time formation of
expected biological complex between FbaB and
PPase was confirmed. However, as we found
out, the complex can be formed only partially.
Most of the enzymes remain in solution as
single macromolecules. This phenomenon is
very interesting task for further biological
investigations.
Nevertheless, the fact of the
formation of the complex is important to
elucidate an involvement of FbaB in such
metabolic regulation processes as stress
adaptation or “quorum sensing”.
1.5
s, nm-1
Figure 2
The Dmax of the complex is in a good agreement
with the sum of maximum sizes of each
individual enzyme, confirming, thus, formation
of FbaB-PPase bio-composite. Interesting,
however, molecular mass (MM) of the complex
in solution (260 kDa), estimated from intensity
scattering at zero angle, is much lower than the
sum of MM of FbaB (340 kDa) and that of
PPase (130 kDa), indicating that only some part
of the individual macromolecules of the
specimens creates the complex. To evaluate
what part of FbaB and PPase participates in the
complex formation, program OLIGOMER was
applied. According to the calculation only 19%
of macromolecules of FbaB and PPase construct
REFERENCES
[1] Lorentzen, E., Pohl, E., Zwart, P., Stark, A.,
Russell, R.B., Knura, T., Hensel, R., Siebers, B..
Crystal structure of an archaeal class I aldolase
and the evolution of (betaalpha)8 barrel
proteins. J Biol Chem. 2003, 278(47), 4725347260.
[2] Rodina, E., Vorobieva, N., Kurilova, S.,
Mikulovich, J., Vainonen, J., Aro, E.M.,
Nazarova, T. Identification of new protein
complexes of Escherichia coli inorganic
pyrophosphatase using pull-down assay.
Biochimie. 2011, 93(9), 1576-1583.
[3] Svergun D. Restoring low resolution
structure of biological macromolecules from
solution scattering using simulated annealing.
Biophys J 76:, 1999, 2879–2886
29
Structural, optical and electrical properties of amorphous silicon
modified by femtosecond laser radiation
A.V. Emelyanov1,2, P.A. Forsh1,2, P.K., A.G. Kazanskii2, M.V.
Khenkin2, Kashkarov1,2, P.G. Kazansky3
1
2
National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia,
Lomonosov Moscow State University, Physics Department, 119991 Moscow, Russia,
3
Optoelectronics Research Centre, University of Southampton, SO17 1BJ, UK
[email protected]
INTRODUCTION
Laser induced crystallization of hydrogenated
amorphous silicon (a-Si:H) is one of the
preferred methods of microcrystalline silicon
(μc-Si) thin film formation for applications in
thin-film electronics and photovoltaics. Despite
both nanosecond and femtosecond laser pulses
can be used for a-Si:H crystallization,
femtosecond
laser-induced
crystallization
includes a non-thermal ultrafast phase transition
followed by a thermal effect process which is
different from rapid thermal melting and
subsequent solidification made by nanosecond
laser pulses [1]. Most of recent studies, devoted
to femtosecond laser-induced crystallization of
a-Si:H, were focused on investigation of
structural properties of laser treated films. It was
found that the laser treatment of a-Si:H film not
only
changes
its
internal
structure
(crystallization process [2]), but also
significantly influences the surface of the film
leading to the submicron spikes formation [3].
Additionally,
a-Si:H
film
treated
by
femtosecond laser radiation in air shows downshifter luminescent features [4].
Electrical and photoelectric properties of
femtosecond laser modified a-Si:H films are
studied in a less substantial extent than structure
transformations, despite they are very important
for optoelectronic applications of modified
silicon films. In this work, we report a
comprehensive study of structural, optical and
electrical properties of a-Si:H films irradiated by
femtosecond laser pulses. We observed that
femtosecond laser irradiation resulted in nonuniform a-Si:H structure modification. Spectral
dependences
of
absorption
coefficient,
measured by constant photocurrent method, of
laser treated a-Si:H films were explained in
terms of hydrogen effusion and additional
formation of defect states in irradiated films
during the laser processing.
EXPERIMENTAL
300 nm thick a-Si:H films were deposited on
silica glass substrates by plasma-enhanced
chemical vapour deposition (PECVD) upon the
decomposition of silane (SiH4) and argon (Ar)
gas mixture at the substrate temperature of
250 oC. Ultrafast laser treatment of a-Si:H films
was carried out with Yb:KGW based
femtosecond system (Pharos, Light Conversion
Ltd.) that delivered pulses of 300 fs with
repetition rate of 200 kHz and wavelength
centered at 1030 nm. The laser beam was
focused via the aspheric lens with a numerical
aperture of 0.16. The focal plane was placed 80
µm above the sample surface in order to
increase the laser irradiation area and avoid
surface ablation. The laser spot had a Gaussian
profile with the diameter of about 15 µm on the
film surface. The samples were irradiated by
continuously scanning with the translation speed
of 5 mm/s. The scanning step was 2 µm. The
highest laser fluence used in the experiments
was 60 mJ/cm2. The laser processing was
carried out in ambient air atmosphere.
Atomic force microscopy (AFM) images have
shown that surface submicron size spikes have
been created upon laser treatment. The spikes are
formed into stripes along the direction of laser
beam scanning. The stripes are spaced from each
30
other roughly by 2 μm matching the scanning
step of the laser beam used for the film treatment.
AFM measurements of film surface profiles
revealed spikes with heights of 15 –40 nm
formed after laser irradiation with the fluences of
30 –60 mJ/cm2. Several processes have been
identified which influence the surface structure
of amorphous silicon film, crystallized by laser
irradiation: hydrogen out-diffusion from a-Si:H,
multiple shot crystallization, differences in latent
heat and thermal conductivity between
crystalline and amorphous silicon, and ambient
condition of the irradiation atmosphere [5].
Explosive evaporation of hydrogen is expected to
be the main reason for surface structures to occur
[1, 5].
The crystalline volume fraction in silicon films
under study was determined from Raman spectra
analysis. A pronounced peak near ωA = 480 cm-1
is observed clearly on spectra of all samples. The
peak corresponds to the amorphous silicon
transverse-optical (TO) vibration mode. Another
peak observed around ωC = 520 cm-1,
corresponding to the crystalline silicon TO mode,
appears on the Raman spectra for the samples
treated with the laser fluences above 50 mJ/cm2.
The integrated intensity of the peaks around 480
and 520 cm-1 were measured to estimate the
crystalline volume fraction fC in studied films.
While increasing laser fluence crystalline volume
fraction grows, reaching the maximal value of
about 36 %. The Raman peak observed around
625 cm-1 is due to presence of hydrogen in the
film and corresponds to wagging vibration of SiH bonds [6]. We used this peak to estimate the
change of H concentration in our films after laser
treatment.
Structural changes caused by femtosecond laser
treatment of a-Si:H films led to changes in their
electrical and photoelectric properties. Dark
conductivity was found to increase dramatically
by 6 –7 orders of magnitude for the sample
treated with the laser fluence of 50 mJ/cm2. It is
known that dark conductivity of μc-Si exceeds
that of a-Si:H by 4 –6 orders of magnitude. So
the abrupt increase of the dark conductivity could
be explained by increase of nanocrystalline part
of the film contribution to charge carriers
transport path through the film. As to
photoconductivity, it increased slightly for the
films treated with higher laser fluences and
reaches the maximum value for the film with
13.4 % crystallinity (treated with laser fluence 50
mJ/cm2). Some decrease of photoconductivity for
the film treated at higher fluence is most likely
connected with macroscopic defects formation in
the treated film due to the processes of spallation
and hydrogen out-effusion.
Spectral dependences of absorption coefficient
αCPM(hυ) were obtained by the constant
photocurrent method. For all treated films the
shape of αCPM(hυ) corresponds to that of
hydrogenated amorphous silicon: exponential
rise in the range of photon energies 1.4 eV < hυ <
1.8 eV, which is attributed to optical transitions
from bands tails states, and so called “absorption
shoulder” at hυ < 1.4 eV, which is attributed to
transitions from defect (dangling bonds) states to
conduction band.
CONCLUSIONS
Structural, optical, electrical and photoelectric
properties of a-Si:H films modified by ultrafast
infrared laser radiation were investigated. By
means of AFM measurements it was observed
that femtosecond laser irradiation resulted in
non-uniform a-Si:H structure modification.
From Raman investigations the levels of
crystalline volume fraction and relative
hydrogen content in studied films were
estimated.
The
dark
conductivity
of
femtosecond laser treated a-Si:H films was
found to increase by about 6 orders of
magnitude compared to pristine a-Si:H, which
was
associated
with
appearance
of
nanocrystalline part contribution to charge
carriers transport path through the film.
ACKNOWLEDGEMENTS
This work was supported by the Russian
Foundation for basic Research (project 12-0233033).
REFERENCES
[1] T.Y. Choi, D.J. Hwang, C.P. Grigoropoulos,
Opt. Eng. 42 (2003) 3383.
31
[2] S. Ryu, I. Gruber, C.P. Grigoropoulos, et al.
Thin Solid Films 520 (2012) 6724.
[3] B.K. Nayak, M.C. Gupta, Appl. Phys. A 89
(2007) 663.
[4] A.V. Emelyanov, A.G. Kazanskii, M.V.
Khenkin, et al., Appl. Phys. Lett. 101 (2012)
081902.
[5] A.A.D.T. Adikaari, S.R.P. Silva, J. Appl.
Phys. 97 (2005) 114305.
[6] N.M. Liao, W. Li, Y.D. Jiang, et al., Appl.
Phys. A 91 (2008) 349.
32
Structure of Luminescent Gluconacetobacter xylinus Cellulose
Nanocomposites investigated by small angle scattering
Ezdakova K1, Kopitsa G.1, Smyslov R.2, Bugrov A.2, Nekrasova T.2,
Khripunov A.2 , Angelov B.3 Pipich V.4, Szekely N.4
1
Petersburg Nuclear Physics Institute NRC KI,
Institute of Macromolecular Compounds RAS, Russia,
3
Institute of Macromolecular Chemistry, Czech Republic,
4
Heinz-Maier-Leibnitz Zentrum, Germany
[email protected]
2
INTRODUCTION
The most perspective materials for modern
nanotechnologies are the biodegradable, safe
materials produced from cheap renewable
natural sources. All these basic conditions are
met by cellulose, which can be derived from an
evolutionarily different sources such as land
plants, algae, and cellulose produced by bacteria
or animals. At present, the cellulose structure of
different evolutionary origin is actively studied.
Nano-gel films of bacterial cellulose by
Gluconacetobacter xylinus (CGx) are widely
used as a template for a variety of organicinorganic composites. Known CGx based
composites contain nanoparticles of silver, gold,
selenium, TiO2, SiO2, CdSe, calcium phosphate,
and fractions shungite [1-4]. Features of the
supramolecular organization of CGx, include a
grid structure formed by nanoscale ribbons, and
a presence of nanochannels between
neighboring nanofibrils in these ribbons formed
during the biosynthesis of cellulose matrix. This
supramolecular organization possesses unique
sorption properties. The CGx ability to absorb
various low-and high-molecular organic
compounds, and inorganic nano-fillers in the
form of a gel film, and in the form of
suspensions (in water, ethanol, toluene, etc.)
makes it a promising material for the creation of
hybrid materials. It can be widely used in
medicine (for example, to create a multipurpose
wound covering, a precursor of bone, cartilage,
etc.), membrane technology, and various fields
of optoelectronics. In this work the
mesostructure of nanocomposites based on
Gluconacetobacter xylinus Cellulose (strain
VKM V-880 was used) is studied by
complementary methods of neutron and X-ray
small angle scattering. The influence of doped
components, like Tb3+, nanoparticles of
zirconium dioxide, on the structural properties is
investigated.
APPROACH
Composites on the basis of CGx with ZrO2 nano
particles including luminescent markers were
synthesized for the first time. In our case, Tb3+
ions as low-molecular salt TbCl3×6H2O or in a
complex with polymer-ligands were used as the
fluorescent markers.
The luminescence spectra were measured on an
LS- 100 (PTI®, Canada) spectrofluorometer.
The choice of the excitation wavelength of 230
or 300 nm was based on the luminescence
excitation spectra of the metal-polymer complex
(MPC). The spectral width of the slit of the
excitation and emission monochromators was
4 nm.
The SANS experiment was performed at the
KWS-2 scattering facility of FRM-II research
reactor using neutrons with the wavelength  =
4.55 Å (/=0.01). The range of momentum
transfer 3·10-3 < q < 0.43 Å-1 was obtained using
three sample-to-detector distances (2, 8 and 20
m). The USANS was performed at the KWS-3
scattering facility of FRM-II research reactor
using neutrons with the wavelength  = 12 Å
(/=0.2). The range of momentum transfer
1.6·10-4 < q < 3.5·10-2 Å-1 was obtained using
33
two sample-to-detector distances (1 and 10 m).
The measured data were calibrated by the
incoherent scattering of plexiglass and corrected
for the sample transmission, background
scattering (from the quartz cell) and detector
response. The resulted data were processed by
the software QtiKWS. Resulting 2D isotropic
spectra were averaged azimuthally. All
measurements were done at room temperature.
The SAXS experiment was performed at the
SAXS facility at IMC in Prague (Czech
Republic) using a pinhole camera (Molecular
Metrology SAXS System) attached to a
microfocused X-ray beam generator (Osmic
MicroMax 002) with the wavelength λ = 1.54Å.
The camera was equipped with a multiwire gasfilled area detector with an active area diameter
of 20 cm (Gabriel design). The range of
momentum transfer 0.005 < q < 1 Å-1 was
obtained using two sample-to-detector distances
418 and 2254 mm. The scattering intensities
were put on absolute scale using a glassy carbon
standard. Resulting 2D isotropic spectra were
averaged azimuthally. All measurements were
done at room temperature and in vacuum.
The hybrid polymer-inorganic biosystem on the
basis of bacterial cellulose with Tb(III) has
beenstudied by luminescent methods. The
content of the lanthanide and ZrO2 nanoparticles
has been varied in a systematic way. It is shown
that changing the amount of TB(III) salt into the
metal-polymeric complex lead to a drastic
increase of the luminescent intensity of the
hybrid systems. Besides, using nanoparticles of
ZrO2, as dopants in the hybrid system of
bacterial cellulose, lead to sesquialteral
increasing of luminescent intensity.
The data from SANS and SAXS demonstrate a
behavior of the scattering curves that is typical
for scattering of systems with complex
multilevel structure [5]. In such structure, large
particles are formed by smaller size particles or
systems consisting of a few heterogeneities with
different size. The following features of the
nanocomposite structure have been established
from the analysis of the small-angle scattering
data:
1. It has been determined that the CGx at the
mesoscopic scale is a system with two-level
fractal structure. The first level of the primary
particles are formed with a characteristic size
Dc1 = 8 nm, and develop a fractal surface with a
dimension Ds1 = 2.37. On the second level the
structure is formed also by a type of a fractal
surface with Ds2 = 2.93.
2. It has been revealed that the addition of Tb3+
ions hardly changes the fractal dimension of the
Ds1 primary particles. At the same time, their
size increase significantly. Thus, in case of
doping CGx with Tb3+ ions using low molecular
weight salt TbCl3 × 6H2O, Dc1 characteristic
dimension increases to 10 nm. In addition, Tb3+
ions that are complexed with a polymeric ligand
lead to a dramatic increase of Dc1 to 20 nm.
3. It has been found that the introduction of
ZrO2 nanoparticles causes significant change in
the local structure of the primary particle.
CONCLUSIONS
In
this work
the
mesostructure
of
nanocomposites based on CGx has been
investigated by USANS, SANS and SAXS
methods. The evolution of the structure of CGx
composites has been traced in dependence on
dopants type.
REFERENCES
1. Maria L.C.S., Santos A.L.C., Oliveira P.C.,
et al. // Materials Letters. 2009. V.63. p. 797799
2. Wang W., Zhang T.J., Zhang D.W., et al.
//Talanta. 2011. V.84. p. 71-77
3. Gutierrez J., Tercjak A., Algar I., et al. //
Journal of Colloid and Interface Science. 2012.
V.377 p. 88-93
4. Yang Z., Chen S., Hu W. et al. //
Carbohydrate Polymers. 2012. V.88. P. 173-178
5.G. Beaucage and D.W. Schaefer, J. NonCryst. Solids 172 –174 (1994) 797.
34
Orientational ordering and packing effects of spindle shaped
particles investigated by spatially resolved coherent SAXS
B. Fischer 1,2, C.Gutt 1,2, J. Wagner 3, F. Lehmkühler 1,2, C. Passow 3,
M. Sprung 1,G. Grübel12,
1
Deutsches Elektronen Synchrotron DESY, Hamburg, Germany , 2 The Hamburg Centre for Ultrafast
Imaging CUI, Hamburg, Germany, 3Chemie, University of Rostock, Rostock, Germany
[email protected]
Hard spheres systems are often used as model
system because their phase diagram only
depends on the volume fraction (Royall et al.
2013, Pusey 1991). In particular such a system
can mimic the properties of the liquid state
(Kirkwood & Boggs 1942, Widom 1967, Weeks
et al. 1971) within an accessible experimental
window of temporal and spatial resolution.
During the last 30 years also anisotropic
elongated particles have been synthesized with a
low polydispersity, such as hematite (Ozaki
1984), silica (Kuijk et al. 2011) or PMMA
particles (Keville et al. 1991, Ho et al. 1993).
Such anisotropic particles show an even more
complicated phase diagram compared to hard
spheres. Additional phases like the smectic and
nematic
phases
appear
(Vroege
and
Lekkerkerker 1992, Glotzer & Solomon 2007).
Here the phase diagram depends not only on the
volume fraction, but also on the shape and the
aspect ratio of the particles (Kuijk et al. 2012).
While their static structure has been intensively
studied in the past (e.g. Kuijk et al 2012,
Mukhija & Solomon 2011), the dynamics of the
anisotropic particles has not been completely
understood yet, only a few studies for the dilute
regime and concentrated regime exist (Reufer et
al. 2012, Wagner et al. 2013, Kuijk et al. 2012).
In this study we use a centrifugal field to
achieve a volume gradient of spindel-shaped
particles, in which an isotropic-nematic phase
transition occurs. Afterwards the preferred
orientation of the particles is studied as a
function of the concentration and of the
confinement due to the capillary wall by means
of small angle (coherent) x-ray scattering.
Hematite particles (α-Fe2O3) were prepared
using a modified controlled precipitation
method of ferric chloride solution which was
first described by Ozaki et al. (1984).
A solution of 0.02 M ferric chlorid solution
containing
sodium
di-hydrogen-phosphate
(NaH2PO4) ranging from 1.0 to 4.5×10−4 M was
refluxed for 48 hours. The axial ratio between
the long and the short axis of the spindles
increases with the amount of NaH2PO4 (Märkert
et al. 2011, Sugimoto et al. 1998).
The coherent small angle X-ray scattering
experiment was carried out at the beamline
P10@Petra III at the Deutsches ElektronenSynchrotron (DESY) in Hamburg (Germany).
For the experiment a high heat load
monochromator was used (Si-111) to set the
energy of the incident beam to 7.0 keV.
To investigate the influence of the confinement
due to the capillary wall the sample was
measured at different distances to the capillary
wall in the dilute regime at a concentration
about =0.144 and concentrated regime with
=0.187.
In the dilute phase the anisotropic particles are
almost completely randomly oriented in the
middle of the capillary. Closer to the wall the
particles start to orientate. In the concentrated
phase the particles are stronger horizontally prealigned than in the dilute regime in the middle
of the capillary. Here still some isotropic
background from randomly oriented particles or
domains can be seen in the pattern.
35
Furthermore, the order increases with higher
concentration.
REFERENCES
Glotzer, S.C., and Solomon, M.J., (2007) Nature
6, 557-562.
Ho, C.C., Keller, A., Odell, J.A., and Ottewill,
R.H., (1993) Colloid Polym. Sci. 271, 469-479.
Kirkwood, J.G., and Boggs, E.M., (1942) J.
Chem. Phys. 10, 394-402.
Kuijk, A., Byelov, D. V., Petukhov,A. V., van
Blaaderen, A., and Imhof., A. (2012). Faraday
Dosciss. 159, 181-199.
Keville, K. M. Franses, E. I., and Caruthers, J.
M., (1991) J. Coll. Int. Sci., 144 103 -126
Kuijk, A., van Blaaderen, A., and Imhof.,A.
(2011). J. Am. Chem. Soc. 133, 2346-2349.
Märkert C., Fischer, B., and Wagner, J., (2011)
J. Appl. Cryst. 44, 441-447.
Mukhija D., and Solomon M.J., (2011) Soft
Matter 7, 540-545.
Ozaki, M., Kratohvil, S., and Matijević, E., J.
Col. Int. Sci., 1984.
Pusey, P.N. (1991) in Liqudis, Freezing and the
Glass Transition J.P.Hansen, D. Levesque and
J. Zinn-Justin, Elsevier 765-942.
Reufer, M.,. Martinez, V.A. Schurtenberger, P.,
and Poon, W.C.K. (2012) Langmuir 28, 46184624.
Royall, C.P., Poon, W.C.K., and Weeks, E.
(2013) Soft Matter 9 17-27.
Sugimoto, T., Wang, Y., Itoh, H., and
Muramatsu, A., (1998) Colloids Surfaces A
134,265-279
Vroege, G.J. and Lekkerkerker, H.N.W., (1992)
Rep. Prog. Phys. 55, 1241-1309.
Wagner, J., Märkert, C., Fischer, B., and Müller,
L., (2013) Phys. Rev. Lett. 110, 048301.
Widom, B., (1992) Science 157, 375-382.
Weeks, J.D., Chandler, D., and Andersen, C.
(1971) J. Chem. Phys. 54, 5237-5247.
36
Highly ordered molecular materials studied by synchrotron
techniques
Stefan Fischer, Josef Hirte, Bert Nickel1
1
Ludwig-Maximilians-Universität,
Geschwister-Scholl-Platz 1, D-80539 München, Germany, Fakultät für Physik and CeNS
[email protected]
Increasing the efficiency of organic electronic
devices such as organic solar cells requires the
understanding and tailoring of interfaces.
Although the structure and morphology of
interfaces is subject to thorough studies, their
impact on electronic processes has not been
fully comprehended.
A bilayer of pentacene and C60 was used as
model system because both molecules are well
known and frequently used in all types of
organic electronics. Nevertheless the detailed
structure of this configuration was still not fully
identified. Atomic force microscopy (AFM) and
grazing incidence wide angle x-ray scattering
(GIWAXS) measurements were performed in
order to get an insight in morphology and
structure of both layers.
Figure 1: GIWAXS map of pentacene and C60
We show that C60 retraces the pyramid like
morphology of the underlying pentacene and
both molecules show crystalline growth.
Pentacene has the well known thin film phase
perpendicular to the surface [00L] [1] and C60
grows in an FCC structure in [111] direction
which can easily get mixed up with an hcp
structure in reflectometry measurements, but the
GIWAXS map, shown in figure 1, could clearly
exclude that.
Electronic measurements with an ambipolar
device show the interface charging between
both layers, but they exceeded the scope of this
poster and can be found in the literature [2].
The second part of the poster treats systems of
ordered lipid structures.
We prepared an inverted hexagonal phase of
lipids on a silicon wafer which was identified
with a GISAXS measurement. We built a
humidity chamber with two different lights in
order to get full control over the ambient
conditions. We use photo switchable molecules
in combination with lipids. These molecules
shall control the phase via the light in the
chamber.
Another project is to reveal how a lipid
membrane covers Au dots on a surface.
Lohmüller et al. [3] assembled Au nanoparticles
in a hexagonal lattice with a lipid bilayer on top.
The question of how the membrane arranges at
the position of the Au remains unclear. That is
why we performed a GISAXS measurement in
order to reveal the formation of the lipid
membrane on top of the nanoparticles.
REFERENCES
[1] Schiefer, S., M. Huth, et al., (2007). J.
Amer. Chem. Soc. 129(34) 10316.
[2] Noever, S. J., S. Fischer et al., (2013). Adv.
Mat. 25(15)2147-2151.
[3] Lohmuller, T., S. Triffo, et al., (2011). Nano
Lett. 11(11): 4912-4918.
37
Spectrometer for hard XFEL based on diffraction focusing
O. Y. Gorobtsov1,2, V. G. Kohn1 and I. A. Vartanyants2,3
1
National Research Center ‘Kurchatov Institute’, Kurchatov Square 1, 123182 Moscow, Russia
2
Deutsches Electronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg, Germany
3
National Research Nuclear University, ‘MEPhI’, 115409 Moscow, Russia
[email protected], [email protected]
Development and construction of hard X-ray
free electron lasers (XFELs) arises the need for
high-resolution spectrometers able to resolve
fine features of FEL individual pulses, that
change chaotically from pulse to pulse. Those
pulses have a fine structure of a typical size of
ΔE/E≈10-6 (for European XFEL). In the
theoretical paper [1] it was shown that it is
possible to make a spectrometer that is able to
resolve these features using just a plane crystal
plate of appropriate thickness. This is
achievable due to dynamical diffraction
focusing effect [2,3].
A sketch of the setup is presented in Fig. 1.
Figure 1: Schematic view of the beamline with
the
diffraction
focusing
spectrometer.
The incoming divergent beam from a secondary
source is focused by a single-crystal plate at
each energy near the Bragg angle. Since the
Bragg angle depends on the energy, X-rays with
different energies will be focused at different
points just behind the crystal under conditions
of focusing. In order to achieve high resolution,
the effective size of the secondary source should
be decreased to about a few micrometers and the
angular divergence of the beam increased to the
necessary value. This can be done, for example,
by positioning compound refractive lenses
(CRLs) upstream from the diffraction focusing
spectrometer (DFS).
Fig. 2 shows intensity at the detector position
(b) from a simulated XFEL pulse (a). Fine
features of the pulse, visible in Fig. 2, (a) are
clearly resolved at the detector position.
Figure 2: (a) Simulated XFEL spectrum with
an incoming photon energy of 12.4 keV, pulse
duration T = 100 fs and spectral width
ΔE/E≈10-3. (b) Corresponding intensity
distribution at the detector after 220 diffraction
of this pulse from a Si crystal. Insets show an
enlarged part of the spectrum.
REFERENCES
[1] V. G. Kohn, O. Y. Gorobtsov & I. A.
Vartanyants, J. Synchrotron Rad. 20, 258-265
(2013).
[2] Kohn V.G., et al., Phys. Status Solidi B, 222,
407–423 (2000).
[3] Afanas’ev, A. M. & Kohn, V. G. (1971).
Acta Cryst. A27, 421–4
38
EXAFS and XRD studies of Ti50Ni25Cu25 shape memory alloy at the
martensitic transformation
Alexey Menushenkov1, Olga Grishina1, Alexander Shelyakov,
Alexander Yaroslavtsev, Nikolay Sitnikov1, Yan Zubavichus2,
Alexey Veligzhanin2,
Joseph Bednarcik3, Roman Chernikov3
1
2
National Research Nuclear University MEPhI, Kashirskoe shosse 31, Moscow 115409, Russia,
Russian Research Centre ”Kurchatov Institute”, Academic Kurchatov square 1, Moscow 123182, Russia,
3
HASYLAB at DESY, Notkestrasse 85, D-22603 Hamburg, Germany.
[email protected]
INTRODUCTION
TiNi-based alloys are some of the most
widespread shape memory alloys (SMA). While
being heated they are able to fully restore their
pre-deformation shape as a result of reverse
martensitic transformation (MT). Under such a
behavior these alloys demonstrate considerable
mechanical force. Due to their unique properties
SMAs are of great interest to find the unusual
ways in development of various important
technical applications [1-2].
Direct and reverse MTs occur in their own
temperature ranges, therefore the material
demonstrates hysteretic properties under phase
transformation. Characteristic temperatures of
MT depend on the alloys chemical composition,
production method and thermo-mechanical
treatment.
The demand of micro- and nano-devices
construction drives the design of new types of SMA
as well as the exploration of local atomic
rearrangement in alloys upon MT. In present work
we investigated the features of crystal structure and
local environment in ternary Ti50Ni25Cu25 SMA by
means of X-ray diffraction (XRD) and extended Xray absorption fine structure spectroscopy (EXAFS)
on synchrotron radiation.
APPROACH
In initial state the samples of three-component
SMA Ti50Ni25Cu25 were thin ribbons obtained
by components melt extrusion from the quartz
crucible through the thin nozzle on the surface
of rotating copper disk, where the sample’s
solidification took place with the rate of
106K/sec. The thickness of the initial amorphous
ribbons was 40−45μm, the average size of
grains was 300÷500nm. Samples were
crystallized by isotropic annealing in the air at
500oC for 4 min. According to differential
calorimetry study the critical temperatures of
direct and revers MT were: Аs=53оС, Аf=65оС и
Мs=57оС Мf=46оС (where Аs and Аf are the
temperatures of austenitic transformation start
and finish, Мs and Мf –temperatures of
martensitic transformation start and finish).
The XRD patterns of Ti50Ni25Cu25 sample were
obtained at beamline BW5 of DORIS-III storage
ring, HASYLAB (DESY, Hamburg) in
temperature range 29-78ºC. High-energy
photons with energy 100 keV of synchrotron
radiation source provide several advantages:
high resolution in real space due to the wide
range of scattering vector, smaller correction
terms (especially for absorption correction. The
EXAFS spectra were measured in transmission
mode above K-Ni (8333 eV) and K-Cu (8979
eV) absorption edges at STM beamline of
Kurchatov synchrotron radiation source
(Moscow, Russia). The EXAFS spectra above
K-Ti (4966 eV) absorption edge at beamline A1
of DORIS-III storage ring (HASYLAB, DESY,
Hamburg). Series of measurements were carried
out upon consistent heating and cooling in the
temperature ranges of direct and reverse MTs.
The fitting of EXAFS spectra was performed
using VIPER [3].
XRD results demonstrate that Ti50Ni25Cu25 alloy
has the B2 type structure in austenitic (high
temperature) phase and B19 in martensitic
phase. Coordinates of Cu and Ni atoms in the
39
unit cell were assumed to be equal. The results
are in good agreement with other investigations
of TiNi-Cu alloys [2,4].
Analysis of EXAFS spectra allowed us to trace
the local atomic displacements upon MT and
observe some discrepancies in the short and
long range order data. The average bond lengths
Ni-Ni and Ni-Cu differ on the local level while
for the undistorted cubic configuration of
austenitic phase these distances should be equal.
Moreover, the atomic displacement in the first
Ni coordination shell (characterized by DebyeWaller factor σ2) is one and a half bigger than
the σ2 value for Cu first coordination shell. The
average Cu-Ti bond length in austenitic and
martensitic phases coincides with the values
obtained from XRD study within the error. In a
similar manner the analysis of K-Ti EXAFSspectra revealed the 0.1 Å discrepancy of Ti-Ni
and Ti-Cu interatomic distances.
The EXAFS data analysis shows that in the
martensitic as in austenitic phase Ti-Ni bonds
have the highest disorder characterized by the
Debye-Waller factor σ2 (both from K-Ti and KNi spectra). This indicates the dispersal of Ti-Ni
bond distances in entire temperature range of
the direct and reverse MT. Therefore, Ti atoms
have the highest degree of mobility upon local
displacements relative to Ni atoms. At the same
time the local structure around Cu atoms
remains
almost
unchangeable
and
is
characterized by the least degree of disorder (the
value of σ2 is considerably smaller). In another
words, the sublattice around Cu atoms has the
largest degree of stability and the least
displacement amplitude. The results of EXAFSspectroscopy reflect anomalies related to the
martensitic transformation, such as unequal
local shifts for different types of atoms. Such
distortions of the local crystal structure of the
alloy may be a kind of structural embryos and
play the role of possible physical centers of
martensitic nucleation. Besides, they may
induce the lowering of the lattice symmetry
during MT, whereby a phase transition from
austenite to martensite may start earlier, i.e. at
higher temperatures.
CONCLUSIONS
The analysis of the EXAFS-spectroscopy data
shows that in the whole temperature range of
MT the bonds involving Ni atoms have the
highest degree of disorder characterized by the
value of the Debye-Waller factor σ2.
Consequently, Ti atoms show greater mobility
in respect to the local displacements relative to
Ni atoms, which are the source of instability,
while the local structure around Cu atoms
remains almost unchanged and has the lowest
disorder. The change in the local environment
around Ni atoms is responsible for the
occurrence of the shape memory effect in the
initial TiNi alloy as in ternary Ti50Ni25Cu25
alloy. Cu atoms occupy the normal positions in
the crystallographic structure and have the
lowest displacement amplitude. Thus, the
introduction of Cu into TiNi alloy contributes to
the stabilization of both phases and influences
the characteristic temperatures and MT
hysteresis value by decreasing the relative
amount of nickel, the change of local
environment around which is responsible for the
origin of martensitic transformation in alloy.
Apparently, this is related to the experimentally
observed sharp decline of the shape memory
effect in the ternary alloy when the copper
content is more than 28 at.%[5].
ACKNOWLEDGMENT
This work is partly supported by Russian
Foundation for Basic Researches (grants 11-0201174-a and 12-07-00811-a).
REFERENCES
[1] Y. Fu, H. Du, W. Huang et al., Sensors and
Actuators A: Physical 112 (2004) 395 –408.
[2] H. Rösner, P. Schloßmacher, A. Shelyakov,
et al., Acta Materialia 49 (2001) 1541–1548.
[3] K.V. Klementev, Journal of Physics D:
Applied Physics 34 (2001) 209.
[4] P.L. Potapov, S.E. Kulkova, A.V. Shelyakov
et al., J. Phys. IV France 112(2003)727-730.
[5] N. Matveeva, Y.K. Kovneristyy,
L.A. Matlakhova, et al. USSR Academy of
science. Izv. Ser. Metally 4 (1987)97–100.
40
Combined electrical and grazing incidence X-ray
measurements of Poly(3-hexylthiophene) thin film formation
Linda Grodd1, Ullrich Pietsch1, Souren Grigorian1
1
OJECTIVE
We present time resolved in-situ grazing
incidence X-ray diffraction (GIXD) studies of
poly(3-hexylthiophene) (P3HT) film formation
with simultaneous conductivity measurements
for direct correlation of structural and electrical
properties. This is important for understanding
the charge transport mechanism and the major
influencing parameters.
INTRODUCTION
During the past decades organic electronics has
become a field of intense research with a wide
range of applications such as organic
photovoltaic (OPV), organic light emitting
diodes (OLEDs) or organic field effect
transistors (OFETs). Easy solution processing
with possibilities of covering large areas, usage
of flexible substrates and inkjet printing makes
conjugated polymers a versatile, low cost
alternative to their rigid inorganic counterparts.
Among the conjugated polymers the wellknown semi crystalline P3HT, which forms
lamellar structures embedded in an amorphous
matrix, provides rather good carrier mobility. At
present, however, the conductivity and charge
carrier mobility of most conjugated polymers
including P3HT remains well below the ones of
inorganic semiconductors. Several studies
showed a strong influence of crystallinity and
orientation on electrical properties (see e.g. [1]
— [4]). Considerable progress in enhancement
of the electrical performance of organic
semiconductors requires better understanding of
the underlying processes.
EXPERIMENTAL APPROACH
A series of in-situ GIXD experiments during
film casting of P3HT from solutions with
different solvents (chloroform, toluene, p-
Department of Physics, University of Siegen, Germany
[email protected]
xylene) and simultaneous conductivity measure-
Figure 1: Experimental setup for in-situ
GIXD and electrical measurements
ments were performed. For this purpose, in-situ
droplet analysis chamber (IDA) allowing for
motor controlled deposition of the polymer
solution on the Si/SiO2 substrate with
source/drain gold electrodes under inert gas
atmosphere was constructed. The source/drain
current was recorded with a Keithley 2600
sourcemeter. X-ray measurements were done at
BL9 DELTA (Dortmund, Germany) and
beamline P08 PETRA III (Hamburg, Germany)
using photon energies of 12.38 keV and 15 keV
respectively.
In the first series of in-situ measurements with
highly volatile chloroform as a solvent we
observed a complex current-structure behavior
with a typical time delay (depending on the
droplet size) of the structural (100) peak with
respect to the maximal current. This suggests
that in the case of fast solidification process
highest conductivity is achieved in the transition
phase from liquid to solid [5].
41
The less volatile solvents toluene and p-xylene,
on the other hand, showed reverse behavior with
the structural peak being fully developed before
the maximum current. The time delay increases
with boiling point of the solvent.
CONCLUSIONS
By in-situ GIXD measurements we observed a
complex structure-conductivity relationship
with a shift between the maximum of
conductivity and the fully developed structural
peak depending on the choice of solvent. It
supports that the overall network connection of
the molecules plays an important role in charge
transport.
ACKNOWLEDGMENTS
The authors that the beamline scientists and
engineers of beamline BL9 DELTA (Dortmund,
Germany) and beamline P08 PETRA III
(Hamburg, Germany) for support during beam
times and BMBF, project no. 05K10PSC, for
funding.
REFERENCES
[1] L. H. Jimison, M. F. Toney, I.
McCulloch, Martin Heeney, Alberto
Salleo, Adv. Mater. 2009, 21, 16,
1568–1572
[2] R. J. Kline, M. D. McGehee, E. N.
Kadnikova, J. Liu, J. M. J. Fréchet, M.
F. Toney, Macromolecules 2005, 38,
3312-3319
[3] R. J. Kline, M. D. McGehee, M. F.
Toney, Nature Materials 2006, 5, 222 –
228
[4] F. S. U. Fischer, K. Tremel, M. Sommer,
E. J. C. Crossland, S. Ludwigs, Nanoscale 2012, 4, 2138-2144
[5] L. Grodd, U. Pietsch, S. Grigorian,
Macromol. Rapid Commun. 2012, 33,
1765−1769
42
Thermotropic phase transitions in model lipid membranes based
on ceramide 6: pH influence
A.Yu. Gruzinov1, M.A.Kiselev2, E.V. Ermakova2, A.V. Zabelin1
1
2
National Research Center “Kurchatov Institute”, Moscow, Russia
Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
[email protected]
The outermost layer of mammalian epidermis –
stratum corneum (SC) –plays an important role
in barrier functions for different external
substances trough skin and for maintaining body
water balance. SC could be viewed as a number
of keratinized dead cells embedded into
extracellular lipid matrix which is a mixture of
ceramides, free fatty acids, cholesterol and its
derivatives. Typical depth of this layer is about
15-25 µm. Nowadays it’s widely accepted that
barrier functions of SC are mainly due to
extracellular matrix.
Model systems are widely used to mimic main
properties of stratum corneum in order to
control components and due to a relatively easy
way of preparing. We investigate four
components model lipid matrix which consists
of synthesized components dissolved in excess
of water. Lipid molecules in water selfassembles into hollow spheric-like structures
(vesicles). Its walls form a two-dimentional
smectic liquid crystal. In order to investigate
this soft-matter systems with low scattering
power it’s obvious to use synchrotron radiation
sources with high brilliance.
We investigate effect of proton concentration
(pH) and temperature changes on the structure
and packing of model lipid matrix of stratum
corneum. Measurements were conducted on
DICSY beamline of Siberia-2 storage ring at
NRC “Kurchatov Institute”. It is shown that
main phase transition temperature decreases
with increasing pH value. Lamellar two-phase
structure translates into one-phase system.
Lamellar repeat distance depends on
temperature and pH.
REFERENCES
M. A. Kiselev, N. Y. Ryabova, A. M.
Balagurov, S. Dante, T. Hauss, J. Zbytovska, S.
Wartewig, and R. H. H. Neubert. New insights
into the structure and hydration of a stratum
corneum lipid model membrane by neutron
diffraction. European biophysics journal: EBJ,
34(8):1030–40, 2005.
M. A. Kiselev. Conformation of ceramide 6
molecules and chain-flip transitions in the lipid
matrix of the outermost layer of mammalian
skin, the stratum corneum. Crystallography
Reports, 52(3):525–528, 2007.
A. Schr¨oter, D. Kessner, M. Kiselev, T. Hauss,
S. Dante, and R. H. H. Neubert. Basic
nanostructure of stratum corneum lipid matrices
based on ceramides [EOS] and [AP]: a neutron
diffraction
study.
Biophysical
journal,
97(4):1104–14, 2009
43
Hard X-ray Nanoprobe at Beamline P06 at PETRA III.
R.Hoppe1, A. Goldschmidt1, F. Seiboth1, P. Boye1,
J.M. Feldkamp1, J. Patommel1,
D. Samberg1, A. Schropp1, S. Ritter1, V. Meier1, S. Hönig1,
C. Baumbach1, A. Schwab1,
S. Stephan1, G. Falkenberg2, G. Wellenreuther2, N. Reimers2,
P. Bhargava2, T. Claußen2, J. Reinhardt2 and C.G. Schroer1,
1
Institute of Structural Physics, TU Dresden, D-01062 Dresden, Germany
2
HASYLAB at DESY, Notkestraße 85, D-22607 Hamburg, Germany
At present, the storage ring PETRA III. at
DESY in Hamburg is the most brilliant
synchrotron radiation source. Hard x-ray
scanning microscopy exploits the high brilliance
particularly well and in 2010 the hard x-ray
scanning microscope of the nanoprobe
endstation of the beamline P06 at PETRA III.
became operational [1]. Since then, experiments
of many kinds were successfully performed
[2, 3].
The nanoprobe instrument is located at 98.2 m
from the source and is based on nanofocusing
refractive x-ray lenses. It is designed to generate
nanobeams with a lateral size of 50 nm and
below and supports transmission, fluorescence,
and diffraction contrast. Thanks to a rotation
stage, even tomographic experiments with
minimal eccentricity and wobble are
accomplishable.
The scanner and detector units are mounted on a
granite block directly deposited the concrete
base unit and are designed for high stiffness but
are also sufficiently versatile to allow for a wide
range of experiments. Samples can be mounted
on a stage with nine degrees of freedom
including a high- precision and high-accuracy
piezo-driven flexure stage on top of the rotation
stage. The detector table allows to position
several detectors (e.g. pixel detector, MAR
camera, light microscope, PCO camera) from
the wide- to the small-angle-scattering regime.
The detectors can also be positioned off-axis in
the horizontal plane for Bragg-angle analysis. A
fluorescence detector is positioned beside the
scanner table facing the sample under 90
degrees.
REFERENCES
[1] Christian G. Schroer, Pit Boye, Jan M.
Feldkamp, Jens Patommel, Dirk Samberg,
Andreas Schropp, Andreas Schwab, Sandra
Stephan, Gerald Falkenberg, Gerd Wellenreuther,
and Nadja Reimers. Hard x-ray nanoprobe at
beamline p06 at petra iii. Nuclear Instruments &
Methods In Physics Research Section Aaccelerators Spectrometers Detectors and
Associated Equipment, 616(2-3), May 2010.
[2] A. Schropp, P. Boye, A. Goldschmidt, S.
Hoenig, R. Hoppe, J. Patommel, C. Rakete, D.
Sam- berg, S. Stephan, S. Schoeder, M.
Burghammer, and C. G. Schroer. Non-destructive
and quantitative imaging of a nano-structured
microchip by ptychographic hard x-ray scanning
microscopy. Journal of Microscopy, 241(1):9–12,
January 2011.
[3] A. Schropp, R. Hoppe, J. Patommel, D.
Samberg, F. Seiboth, S. Stephan, G.
Wellenreuther, G. Falkenberg, and C. G. Schroer.
Hard x-ray scanning microscopy with coherent
radiation: Beyond the resolution of conventional
x-ray microscopes. Applied Physics Letters, 100
(25), 2012.
44
Fabrication and quality control
of the X-ray diffraction gratings at ANKA
D. Karpov1, V. Weinhardt1,2, D. Kunka3, F. Chen1, T. Baumbach1
1
INTRODUCTION
In the past years x-ray imaging technique at the
microscale has shown great potential in the
material research. Due to the high penetration
depth of the x-rays it is a non-destructive
approach for studying of the volumetric
samples. X-ray absorption contrast is limited to
the samples which absorb minimum 20% of xrays.
Phase contrast imaging has a high sensitivity to
small differences in electron density of the
materials and unlike the absorption contrast it
has a better contrast at higher photon energies.
The quality of the phase contrast images
obtained with Talbot interferometer depends on
the quality of the X-ray diffraction gratings. At
KIT in collaboration between Institute of Photon
Science and Synchrotron Radiation (IPS),
ANKA synchrotron and Institute for
Microstructure Technology (IMT) we have
established process of fabrication and quality
control of the gratings. In this work we
introduce new approach for the gratings quality
evaluation.
Affiliation one, 2Affiliation two, …
[email protected]
FABRICATION
The fabrication of the gratings is done at LIGA
beamline of ANKA synchrotron. In the first step
of LIGA fabrication process a photoresistive,
but sensitive to X-rays, polymer is attached to a
substrate. In the next step it is exposed to the
beam of high energy synchrotron radiation
through a specially designed mask of a strong
X-ray absorbing material. After the exposure
residual photoresist is chemically removed.
Resulting structure is later filled with a desired
metal by the process of electrodeposition [2].
TALBOT GRATING INTERFEROMETRY
X-ray Talbot grating interferometry is an
imaging method based on Talbot self-imaging
effect. The method provides 3 contrast modes
(absorption, phase and dark-field contrast)
simultaneously. Talbot interferometry employs
two diffraction gratings: phase grating (G1) and
absorption grating (G2). Absorption grating is
moved in the direction xg and the intensity
distribution in each pixel of the detector is
recorded at each step. The variation of the
intensity can then be expressed as truncated
Figure 1. Principle scheme of Talbot grating interferometer
45
Fourier series [1]:
Contrast-to-Noise ratio (CNR) were calculated
on the ROIs as following:
where i, j are the pixel coordinates, p2 is a
period of absorption grating G2.
where is mean signal, σ is standard deviation
of the signal, and indices s and b stand for
sample and background, respectively.
Absorption contrast can be calculated as
, where indices r and s stand for
the reference scan and the scan with a sample,
respectively. To obtain the differential phase
contrast following expression can be used:
, and for the dark-field contrast
. It is possible to obtain
the visibility map of the grating while
performing the scan without a sample as
.
QUALITY CONTROL
For the quality assessment of the fabricated
gratings Talbot grating interferometry has been
employed at the TopoTomo beamline of ANKA
synchrotron. It was shown that visibility map of
the grating and its visual inspection is not
sufficient to conclude on the grating's quality. It
was proposed to use test sample with known
geometry for which expected phase contrast can
be easily calculated (e.g. PMMA cuboid) for a
qualitative visual inspection of the resulting
phase contrast image along with visibility map.
Moreover, to make the process quantitative it
was decided to use three regions-of-interest
(ROI). Signal-to-Noise Ratio (SNR) and
Table I. Results for 879p-0166_2_WP30 grating
Grating SNRref SNR1 SNR2 CNR Visibility
Nr1
6,05
21,9
0,16
6,7
18,75
Nr2
2
2,5
0,6
2,12
16,5
Nr3
78,9
69,3
73,7
1,84
15,6
By that it is possible to perform more accurate
comparison measurements of the gratings with
different design.
CONCLUSION
The new approach in the X-ray diffraction
gratings quality assessment based on qualitative
and quantitative inspection of the phase contrast
image of the test sample has been described.
The approach can provide more information
required for the evaluation of the gratings
fabrication and help to select the most suitable
grating for the experiments which will result in
better data quality.
REFERENCES
1. Altapova et al. Opt. Express, 20(6):64966508, Mar 2012
2. Reznikova et al. Microsystem Technologies,
14:1683-1688, Oct 2008
Figure 2. Visibility map (left) and phase contrast of the test sample (right)
for the 879p-0166_2_WP30 absorption grating
46
Study of Silicon-on-Sapphire structural quality by X-ray
diffractometry, reflectivity and TEM methods
Blagov A.E.1, Vasiliev A.L.1, Kondratev O.A.1, Pisarevskiy Yu.V.1,
Prosekov P.A.1, Seregin A.Yu.1
1
A.V. Shubnikov Institute of Crystallography Russian Academy of Sciences,
Leninskij prospect 59, Moscow, Russia
[email protected]
The structures of the Silicon on sapphire (SOSstructure) are usually used in microelectronics,
including the temperature sensors, highperformance radio-frequency (RF) applications
and radiation-resistant integrated circuits and
devices (UltraCMOS, RFICs, digital step
attenuators etc). In the manufacture of these
structures, using r-type sapphire substrates and
silicon layer orientation [100], the application of
epitaxial growth involving a silicon purification
process raises a number of technical problems to
fabricate a high-quality structures that may even
lead to the destruction of the substrate. Those
problems normally caused by crystal defects
both in the epitaxial Si-layer and interfacial
structure: twinning, misorientation, dislocations,
1)
inhomogenity and lattice strain, etc. The
purpose of the present study is to develop a
comprehensive technique that allows us to
observe the SOS-structure quality at every phase
of production. Two SOS-structures, 150 mm
diameter, thicknesses of Si-layer 0.3 and
0.1 μm, were studied by X-ray methods and
electron microscopy.
Samples were observed by transmission electron
microscopy (TEM). The twins, domains with
different orientations and other defects were
found in both samples.
Samples were investigated using high-resolution
X-ray diffraction and X-ray reflectometry. In
the high-resolution diffraction pattern for both
samples series of rocking curves for substrate
2)
Fig. I. TEM images: 1) – 0.1 μm sample 2) – 0.3 μm sample (arrows indicate
areas of twinning).
47
and for silicon layer at different points were
measured, and also measured the degree of
disorientation of the substrate and silicon layer.
For 0.3 micron structure was performed search
of domains with an orientation other than [100]
founded by microscopy. According to the results of
X-ray reflectometry the thickness of the silicon
layer, the thickness of the transition layer was
determined, and the density profile was built.
The work was supported by RF Ministry of
Education and Science (agreement 8574).
48
Monte-Carlo simulations of thermal neutron filter and neutron
guide system for REVERANS reflectometer
P. Konik1, E. Moskvin1,2
1
INTRODUCTION
Monte Carlo technique is very useful for
numerically analyzing all the components of
neutron instruments before installing and allows
optimal involving a large number of variables.
Random numbers are used to select values for
each variable and the resulting values are
averaged. In order to check new concepts in
polarized neutron instrumentation or to find the
best ways of upgrading existing devices, it is
nowadays inevitable to perform thorough Monte
Carlo (MC) simulations. Analytic calculations
are still another important method to check new
ideas and even simulations in simple cases.
However, MC methods can accurately handle
very complex geometries, and multidimensional parameter spaces. Thus new ideas
in neutron techniques need initially to be
materialized in the MC simulation software.
Virtual instruments based on Monte-Carlo
techniques are now integral part of novel
instrumentation development and the existing
codes (McSTAS and Vitess) are extensively
used to define and optimize novel instrumental
concepts.
INSTRUMENT
REVERANS
is
a
polarized
neutron
reflectometer with the vertical scattering plane.
The instrument is the only of such type in
Russia. It allows to investigate structure of both
free surface of liquids and interface. Physical,
chemical and biological processes occurring on
a free surface and on boundaries between
different types of liquid systems and gas or solid
can be researched. Such systems are organic and
inorganic liquids, solutions, suspensions and
colloid solutions of nanoparticles, liquid
crystals, etc.
Petersburg Nuclear Physics Institute,
2
Saint Petersburg State University
[email protected]
THERMAL NEUTRON FILTER
Today REVERANS instrument is situated on
the reactor WWR-M and is being moved from
beam 12 to beam 3, which has much higher
intensity. This beam gives a straight view to the
active zone of the reactor and thus provides a lot
of hot neutrons, that have to be filtered, because
reflectometer is working with 6 Å neutrons.
The main part of this thermal neutron filter is a
multilayer mirror (m = 2.25). A specific V-like
shape collimators installed before and after the
mirror. These collimators are inclined by a
critical angle to the mirror. So, cold neutrons are
reflected by mirror, while hotter than 6 Å
neutrons ignore mirror and are absorbed by iron
surroundings of the device. The V-shape of
collimators in vertical direction is needed to
achieve the required vertical divergence.
Using Monte-Carlo technique we defined
optimal position and geometry, size and cover
type of filter, geometrical properties of
collimators.
NEUTRON GUIDE SYSTEM
In not such distant future REVERANS will be
moved to the neutron guide hall of the new
high-flux reactor PIK. It is essential to construct
a system of neutron guides filtering hot
neutrons, giving as high vertical divergence as
7o, allowing effective monochromatization and
polarizing of whole beam.
Different types of guides (either straight, elliptic
or parabolic) and their combinations are
inspected and a proposal for a complex solution
has to be formulated.
ACKNOWLEDGMENT
Authors wish to thank V. Zabenkin for useful
discussions on a subjec
49
Influence of radiation dose on the structure
of cytochrome c nitritereductase
Lazarenko Vladimir1, Polyakov Konstantin2
1
NRC “Kurchatov Institute”, 2 Engelhardt Institute of Molecular Biology
[email protected]
The main purpose of this research was to show
the dynamics of the enzymatic activity of the
protein expense of increasing the dose absorbed
during the collection of diffraction data.
INTRODUCTION
Identify the principles of functioning of
enzymes based on the knowledge of their spatial
(tertiary and quaternary) structure is one of the
main tasks of protein crystallography. Currently
the most accurate model of the spatial structure
provides a method of X-ray analysis, based on
the analysis of X-ray diffraction from crystals of
the studied object. However, X-ray analysis can
only give a static picture, but when we work
with proteins, we often want to see a dynamics.
The object of study of this work is octohaem
cytochrome c nitrite TvPaR, derived from the
bacterium Thioalcalivibrio paradoxus [1].
TvPaR monomer comprises 553 amino acid
residues and has a molecular weight of 64 kDa.
Cytochromes catalyze nitrite reduction reaction
of nitrite and ammonia to hydroxylamine and
sulphite to sulphide. These reactions need
additional electrons, which brings by another
protein.
APPROACH
During data collection, analysis of X-ray crystal
protein absorbs some radiation dose [2]. This is
because all the photons of ionizing radiation,
such as interacting with a crystal, only 8% are
diffracted, and the rest goes to the photoelectric
effect and the Compton effect [3]. Knocked out
by photoelectric effect and Compton effect,
electrons continue to interact with the atoms of
the crystal, and will gradually reduce the protein
molecules [4].
These electrons may be used for the enzyme
catalytic reaction. Then more we have irradiated
the crystal, then more electrons will go into the
active site and therefore will advance the further
reaction. Due to the collecting of several data
sets, we can get the required dose and as a
result several static pictures which will see the
gradual progress of the reaction.
Were recorded in succession 5 complete sets of
diffraction data with an increasing dose of
ionizing radiation. Under the action of ionizing
radiation, the recovery of the protein causes the
enzyme nitrite reduction reaction.
Figure 1. The active site of TvPaR after dose of
0,4 MGy (set №1).
On the Figure 1 we can see the active site of
TvPaR after dose of 0,4 MGy. Catalytic
residues of histidine, arginine and tyrosine,
haem and nitrite were selected. Green denotes
the electron density 2Fobs — Fcalc with depth
in one sigma. Nitrite have a fully occupation.
50
CONCLUSIONS
1) It is shown that under the action of ionizing
radiation (with increasing dose) we were able to
see the initial stage of the reduction of nitrite to
ammonia.
2) It has been suggested as the first stage
enzymatic reaction is the conversion of nitrite
into NO molecule.
Figure 2. The active site of TvPaR after dose of
2 MGy (set №5).
Not the same picture we can see on the Figure 2,
after bigger dose. One oxigen was removed
(oxigen 2, the other one will be the oxigen 1).
After dose of 2 MGy the NO molecule and
water, both with half occupation, are sitting in
the active site.
In this way we were able to see the initial stages
of the recovery of nitrite to ammonia occurring
under the influence of ionizing radiation. Firstly
the oxigen 2 are splitted off, then the remaining
molecule NO rotated so that the straight line
passing through one oxygen and nitrogen
becomes perpendicular to the heme (it is shortlived state, it can’t be detected by X-ray
analysis) then oxygen 1 is turned on and place
of oxygen 2. This explains the gradual
disappearance of oxygen 1, while oxygen 2 are
cutting off much slower. After a dose of 2 MGy
oxygen 1 is no longer visible, because he turned
around and took the free place of oxygen 2.
REFERENCES
[1] Tamara Tikhonova, Alexey Tikhonov,
Anton Trofimov, Konstantin Polyakov,
Konstantin Boyko, Eugene Cherkashin, Tatiana
Rakitina, Dmitry Sorokin and Vladimir Popov,
Comparative structural and functional analysis
of two octaheme nitrite reductases from closely
related Thioalkalivibrio species; FEBS J. 2012
Nov, 279, (21), 4052-61
[2] James M. Holton, A beginner’s guide to
radiation damage, J. Synchrotron Rad. (2009).
16, 133–142
[3]
Garman E. F., Radiation damage in
macromolecular crystallography: what is it and
why should we care? Acta Cryst. (2010). D66,
339–351
[4]
Midori Sato, Naoki Shibata, Yokio
Morimito, Yuki Takayama, X-ray induced
reduction of the crystall of high-molecukar
weight
cytochrome
c
revealed
by
microspectroscopy, J. Synchrotron Rad. (2004).
11, 113–116
51
Phase dynamics of Josephson junctions
S. Yu. Medvedeva1,2 and Yu. M. Shukrinov 1
1
2
BLTP, JINR, Dubna, Moscow Region, 141980, Russia
Moscow Institute of Physics and Technology (State University),
Dolgoprudny, Moscow Region, 141700, Russia
In the capacitively coupled Josephson junctions
model with diffusion current (CCJJ+DC model)
[1, 2] the stacks with N intrinsic Josephson
junctions is described by a system of dynamical
equations
where Tmin and Tmax determine the interval for
the averaging. After completing the voltage
averaging for current I, the current I is increased
Time
0 Tp
Tf
2Tf
It
3Tf
It +2δI
the
gauge-invariant
phase
differences
between superconducting layers (S-layers). Here
is the phase of the order parameter in Sis the vector potential in the barrier.
layer l,
Time t is normalized to the inverse plasma
(
, Ic - critical
frequency
current, C - capacitance), the voltage - to the
, the current - to the
value
critical current Ic.
For a given set of model parameters N, α, β, γ
we simulate the CVC of the system. A change in
these parameters changes the branch structure in
the CVC essentially. Their influence on the
CVC in the CCJJ and CCJJ+DC models was
discussed in Refs.[2, 5, 6]. To calculate the
voltages in each point of the CVC (for each
value of I), we simulate the phase dynamics
(t) using the fourth-order Runge-Kutta
method. Scheme of numerical procedure is
presented in Fig. 1. The average voltage is given
by
(2)
It +3δI
Current
for
tN=Tf/Tp
I
Parameters of simulation:
trt - recording time;
Tp - step in time;
t - number of steps in time;
tN - total number of
time steps;
ti - initial number for
averaging procedure;
Tf - size of time domain;
Ti - initial time for
averaging procedure;
It - initial current value
for time dependence
recording;
δI - step in current;
It +δI
(1)
trt
trt=t*TP+Tf (It-I) / δ I
0<t<tN
Tp = 0.05;
Ti = 50 - 500;
Tf = 250 - 25000;
FIG. 1 Scheme of numerical procedure for the
phase dynamics in coupled Josephson junctions.
or decreased by a small amount δI to calculate
the voltages at the next point of the CVC. We
use the distribution of phases and their
derivatives achieved in the previous point of the
CVC as the initial distribution for the current
point. Finally we obtain the total dc voltage V of
the stack by
(3)
Using Maxwell equation
, where
ε and ε0 are relative dielectric and electric
constants, we express the charge density
in the S-layer l by the
voltages Vl and Vl+1 in the neighbor insulating
layers, where
, and is Debye
screening length. The charge dynamics in the Slayers determines the features of current voltage
characteristics of the coupled Josephson
junctions.
Solution of the system of dynamical equations
for phase differences gives us the voltages as
functions of time Vl(t) in all junctions of the
52
stack, and it allows us to investigate the time
dependence of the charge in each S-layer. The
recorded time is calculated by formula
. We use mostly Tf =
1000, δτ = 0.05 and δI = 0.0001 in our
simulations.
[1] M. Machida, T. Koyama, A. Tanaka and M.
Tachiki, Physica C 330, 85 (2000).
[2] Yu. M. Shukrinov, F. Mahfouzi, P. Seidel.
Physica C449, 62 (2006).
[3] T. Koyama and M. Tachiki, Phys. Rev. B
54, 16183 (1996).
[4] M. Machida, T. Koyama, and M. Tachiki,
Phys. Rev. Lett. 83, 4618 (1999).
[5] H. Matsumoto, S. Sakamoto, F. Wajima, T.
Koyama, and M. Machida, Phys. Rev. B 60,
3666 (1999).
[6] Yu. M. Shukrinov and F. Mahfouzi, Physica
C 434, 6 (2006).
53
Three-dimensional artificial spin ice in nanostructured Co on an
inverse opal-like lattice
A.A. Mistonov1, N.A. Grigoryeva1, H. Eckerlebe2,
N.A. Sapoletova3, K.S. Napolskii3, A.A. Eliseev3, D. Menzel4,
S.V. Grigoriev1,5
1
Faculty of Physics, Saint-Petersburg State University, Saint Petersburg, 198504, Russia;
2
GKSS Forschungszentrum, Geesthacht, 21502, Germany;
3
Department of Materials Science, Moscow State University, Moscow, 119992, Russia;
4
Institute of Condensed Matter Physics, Braunschweig, 308108, Germany;
5
Petersburg Nuclear Physics Institute, Gatchina, Saint Petersburg, 188300, Russia
[email protected]
We study magnetic properties of the threedimensional ferromagnetic cobalt net ordered
in the face centered cubic (fcc) structure –
inverse opal-like structure (IOLS). The Co
IOLS was prepared using a templating
technique in three steps. First, polystyrene
spheres with diameter of 540 nm form on the
conductive substrate a colloidal crystal film
(template) with fcc structure with the area of
1 cm2 and the thickness of 14 μm. Then,
electrochemical crystallization of cobalt in
the voids between the spheres was carried
out. Finally, microspheres were dissolved in
toluene. [1,2].
The basic element of this structure is a
complex of quasitetrahedron, quasicube and
another quasiterahedron connected along the
spatial diagonal of the cube (<111>-type).
The idealized element is presented in Fig. 1a.
In reality the faces of these tetrahedra and
cube are concave, since they were formed by
the surface of the spherical particles.
The SANS experiments were performed at
the SANS-2 setup in Geesthacht (Germany).
A neutron beam with a wavelength
λ = 1.2 nm, and a divergence η = 1.5 mrad
was used. The scattered neutrons were
detected by a PS detector set at a distance
21.5 meters from the sample. The Q-range
was covered from 5 to 50 μm-1 with a step of
0.5 μm-1. Cobalt IOLS film was oriented
perpendicularly to the incident beam. In this
position the [111] axis of the fcc structure
with the 3-fold symmetry was oriented
parallel to the incident beam. The recorded
neutron diffraction patterns consist of
several clearly resolved sets of hexagonally
arranged reflexes (Fig. 1b). The external
magnetic field H up to 1.2 T was applied
perpendicular to the incident beam and
along the [ 1 2 1 ] axis of the IOLS.
Fig. 1. Projection of idealized basic element
of IOLS on (111) plane with attached
tetrahedra of four such neighbouring
elements (a) and neutron diffraction
patterns for Co IOLS in field H = 294 mT
applied along [ 1 2 1 ] axis. The Miller
indexes of the reflections corresponds to the
fcc structure with the lattice constant of
a0 = 0.76 ± 0.01 μm.
54
SANS experiments have revealed a
magnetization distribution coinciding with
the spatial net of IOLS. We have constructed
the model of this distribution, using the «icerule» concept [3,4].
Our model requires the magnetic flux
conservation in tetrahedra and cubes of IOLS
to minimize the magnetic energy of the
system. We compared the experimental
SANS data with the scattering intensity
predicted from the model and found a
satisfactory agreement. Thus we show that
the magnetic system of IOLS is determined
Fig. 2. Magnetization distribution in IOLS for the different state of the remagnetization process
(a-f). The Ising-like magnetic moments directed along the <111> axes are shown by arrows in
(220), (022) and (202) planes. Those of them, which lie in higher plane are lighter.
by the generalized «ice-rule» model and
results in the macroscopically measured
component of magnetization perpendicular to
the applied magnetic field. The local
distribution of the magnetization at the
different stages of the remagnetization
process is presented in Fig. 2. Each stage is
characterized by the critical magnetic field
Hci corresponding to the remagnetization of
the different elements of the basic unit cell of
the magnetic net of the IOLS.
D. Yu. Chernyshov, A. V. Petukhov, D. V.
Belov, A. A. Eliseev, A. V. Lukashin, Yu.
D. Tretyakov, A. S. Sinitskii, H. Eckerlebe,
Phys.Rev. B, v. 79, 045123 (2009)
[2] N. A. Grigoryeva, A. A. Mistonov, K.
S. Napolskii, N. A. Sapoletova, A. A.
Eliseev, W. Bouwman, D. V. Byelov, A. V.
Petukhov, D. Yu. Chernyshov, H.
Eckerlebe, A. V. Vasilieva, and S. V.
Grigoriev, Phys.Rev. B, v. 84, 064405
(2011)
ACKNOWLEDGMENT
Work was supported by the DAAD program
«Dmitry Mendeleev» 2012 and RFBR grant
№ ofi-m 12-02-12066/12.
[3] M. J. Harris, S. T. Bramwell, D. F.
McMorrow, T. Zeiske and K. W. Godfrey,
Phys. Rev. Lett., v. 79, 2554 (1997).
REFERENCES
[1] S.V. Grigoriev, K.S. Napolskii, N.A.
Grigoryeva, A.V. Vasilieva, A. A. Mistonov,
[4] A.P. Ramirez, A. Hayashi, R.J. Cava, R
Siddharthan, and B.S. Shastry, Nature,
v. 399, 333 (1999)
55
Applying the Synchrotron Radiation for the Studying Phaseformation during Combustion of
the Aluminum Nanopowder in Air
Andrey V. Mostovshchikov, Alexander P. Ilyin, Nikolay
A. Timchenko
Tomsk Polytechnic University
[email protected]
INTRODUCTION
Scientific and practical interest in aluminum
nanopowders is firstly due to the prospects of
their use in rocket propellants, hydrogen power
engineering,
and
powder
metallurgy.
Meanwhile, an example of specific application
of Al nanopowders is obtaining aluminum
nitride by combustion in air [1].
The modern electronics industry widely uses
substrates of aluminum nitride because it has
high thermal conductivity and is a dielectric, so
that studying the mechanism of aluminum
nitride formation and improving its production
technology are urgent problems [2].
At atmospheric pressure, aluminum nitride does
not form a liquid phase, and it grows only from
a gas phase. In the classical view, this process
requires low temperature gradients and small
vapor supersaturation and should occur at low
rates for a relatively long time [3]. Under high
temperature gradients or large supersaturation,
i.e., under nonequilibrium conditions, aluminum
nitride whiskers are formed [2]. At the same
time, combustion of aluminum nanopowder
under the influence of a constant magnetic field
produces aluminum nitride microcrystals of
hexagonal shape [2].
In the combustion of aluminum powder with
free access of air, the main final product is
aluminum nitride in the form of an independent
crystalline phase. In this phase, the weight
content of aluminum nitride is 30–90% [1]. The
combustion of an Al nanopowder sample in the
form of a freely poured cone or a compacted
cylinder occurs in two stages: the first is
characterized by low temperatures due to
burnout of the hydrogen absorbed by aluminum
nanoparticles, and the second corresponds to
aluminum oxidation with oxygen and nitrogen
in the mode of thermal explosion. The thermal
explosion is characterized by a sharp increase in
the sample temperature from 800 to 2400◦C for
5–10 s, and is not accompanied by expansion of
the burning sample (combustion products) and
formation of a high-velocity gas stream. The
second stage of combustion is the formation of
aluminum nitride in the form of whisker crystals
[2]. Despite the studies performed, the stages of
phase formation in the combustion of Al
nanopowders have not been studied in sufficient
detail.
The purpose of this study is to establish the
sequence of formation of product crystalline
phases during combustion of pressed aluminum
nanopowder in air using synchrotron radiation.
EXPERIMENTAL PROCEDURE
The samples were prepared by compacting the
aluminum nanopowder in a steel press mold
under a pressure of 7.5 MPa. The diameter of
the obtained cylinders was 10 mm, the height
was 7 mm, and the weight 0.4 g.
The experiments were performed in the Budker
Institute of Nuclear Physics, Siberian Branch of
the Russian Academy of Sciences, Novosibirsk,
using the Station “Precision Diffractometry II”
(SR channel No. 6 of the VEPP-3 electron
storage ring), and the wavelength of the incident
radiation was 1.0731 Å. Detailed information
about the equipment and parameters and
photographs of the diffractometer with the OD3M one-coordinate detector are available on the
Internet [4].
56
We placed the sample on the work table of the
diffractometer, focused the synchrotron
radiation on the sample surface, initiated
combustion, and recorded diffractograms
(fig. 1) of the surface of the burning compacted
aluminum nanopowder [5].
According to the results obtained, aluminum
initially reacts with air oxygen, which heats the
sample. In the range of 8–15 s from the
beginning of combustion, the combustion
products are in the gas phase and are not
detected using synchrotron radiation. Formation
of the crystalline phases of the products on the
sample surface starts at the 15th second after the
initiation of combustion. Based on the ratio of
the reflection intensities, the main products of
combustion of aluminum on the sample surface
and in the volume of the sample are Al2O3 and
AlN, respectively.
According to the diffractograms of the burning
sample surface obtained using the synchrotron
radiation (fig. 1), the formation of the crystalline
phases goes through the following stages.
1. After initiation of the combustion and heating
of the aluminum nanopowder, the intensity of
the diffraction maxima of metallic aluminum
decreased: the diffractogram shows the first
Fig. 1. Diffractograms of the burning aluminum
nanopowder sample (surface)
REFERENCES
1. A. P. Il’in and L. T. Proskurovskaya, “TwoStage Combustion of an Ultradispersed
Aluminum Powder in Air”, Combust., Expl.,
Shock Waves, 26 (2), 190–192 (1990).
2. A. P. Il’in, A. V. Mostovshchikov, and L. O.
Root, “Growth of Aluminum Nitride Single
Crystals under Thermal Explosion Conditions”,
stage of the two-stage combustion process,
which involved melting of, aluminum inside the
powder nanoparticles at a temperature 660◦ C.
2. During the reaction of nitride formation,
which corresponds to the second stage of
combustion, the diffractogram did not show
reflections of metallic aluminum and the
temperature of the sample abruptly increased.
3. About 15 s after the initiation of combustion,
the crystalline phases of aluminum oxide and
silicon oxynitride (Al5O6N) began forming.
4. The formation of the crystalline phase of
aluminum nitride and metallic aluminum was
observed after about 22 s from the start of
combustion.
CONCLUSIONS
1. In the products of complete combustion of
pressed samples of aluminum nanopowder, the
main phase (100% reflex) is aluminum nitride,
and the content of the remaining crystalline
phases does not exceed 27% (fig. 2).
2. In the combustion of aluminum nanopowder,
aluminum γ-oxide is the first to form.
3. The formation of aluminum probably occurs
by successive displacement of oxygen by
nitrogen from the aluminum oxide.
Fig. 2. Diffractogram of the final products (bulk)
Technical Physics Letters, 2011, Vol. 37, No.
10, pp. 965–966.
3. A. Laudise and R. L. Parker, The Growth of
Single Crystals, Vol. 25: Solid State Physics,
Academic Press, NewYork–London, 1970).
4. Siberian Synchrotron and Terahertz Radiation
Center, Budker Inst. of Nuclear Physics,
57
Siberian Branch, Russian Academy of Sciences,
Novosibirsk; http://ssrc.inp.nsk.su/CKP/.
5. A. P. Il’in, A. V. Mostovshchikov, N. A.
Timchenko, “Phase Formation Sequence in
Combustion of Pressed Aluminum Nanopowder
in Air Studied by Synchrotron Radiation”,
Combust., Expl., Shock Waves, 49 (3), 320–324
(2013).
58
Structure of supported catalysts: x-ray synchrotron diagnostics
in situ
Murzin V.Y.1, 2, Zubavichus Y.V.1, Veligzhanin A.A.1, Bruk L.G.3,
Bukhtiyarov V.I.4
1
National Research Center «Kurchatov Institute»
Topchiev Institute of Petrochemical Synthesis RAS
3
Lomonosov Moscow State University of Fine Chemical Technologies
4
Boreskov Institute of Catalysis SB RAS
[email protected]
2
INRODUCTION
Catalysts play important role in many important
industrial chemical processes. In order to
improve their properties and get more active,
selective, stable or environmentally friendly
catalysts we should know how they work at
different structure levels. Moreover, it is
important to analyze the structure of catalysts
during the process or in situ.
X-ray methods are the main tools for such
structure analysis. But often there is a case that
catalysts (especially supported) contain only a
few percent of active component. Therefore, to
analyze the structure of such components highly
sensitive methods are required. The best choice
is to use synchrotron radiation sources which
Fig.1. Photo of the Structural Materials Science end-station at the NRC “Kurchatov Institute”. SR – synchrotron radiation.
I0 –current in the first ionization chamber (before the sample), It –current in the second ionization chamber (after the
sample).
59
analyzed in situ using XRD, XANES and
EXAFS methods at the Structural Materials
Science end-station of the National Research
Center “Kurchatov Institute” [1] (Fig.1).
have intensities orders of magnitude higher than
conventional x-ray tubes.
In this work two catalytic systems supported on
gamma-alumina (containing 0.8 wt.% Pt and 1.5
wt.% Pd / 3.5 wt.% Cu correspondingly) were
1.6
Normalized Absorption, arb.units
1.4
ab
1.2
f
e
d
c
i
gh
jk m
l
1.0
0.8
1.5
0.6
1.0
0.4
0.5
0.2
0.0
11555
0.0
11520
11540
11560
11580
11600
11560
11620
11565
11640
11570
11575
11660
Energy, eV
Fig.2. In situ XANES measurements of the Pt catalyst during methane oxidation. Increase of the O2
concentration in the IRM: a) 0.5% b) 1.0% c) 1.5% d) 2.0% e) 2.5% f) 3.0% g) 4.0% and subsequent decrease of
the O2 concentration in the IRM: h) 3.0% i) 2.5% j) 2.0% k) 1.5% l) 1.0% m) 0.5%. Conditions: 400oC, 1%
vol.% CH4. Inset shows enlarged view of XANES spectra for the catalyst d) (solid line) and j) (dashed line)
compared to references Pt foil (filled circles) and K2Pt(NO2)4 (open circles).
RESULTS
In situ XANES studies of the Pt catalyst for
methane oxidation have confirmed the
concentration hysteresis in the effective Pt
oxidation state (Fig. 2) [2]. Evidently, there are
two forms of platinum stable within specific
concentration ranges of oxygen in the initial
reaction media (IRM). These stability ranges
depend on the direction of the oxygen
concentration variation. The Pt switches from
fully metallic to partly oxidized state at 2.0-3.0
vol.% when increasing the oxygen concentration
and at 1.5-1.0 vol.% when decreasing it. The
transition of supported platinum to the active
state is probably caused by partial reduction of
PtO2 species under the fuel-rich conditions.
In situ XRD, XANES and EXAFS studies of the
PdCu catalyst for low-temperature CO oxidation
have shown that the initial catalyst contain
palladium in the complex form [PdHal4]2- (Hal
= Cl, Br) on the surface of gamma-Al2O3 and
copper in the crystalline form Cu2(OH)3Hal.
There was no evidence of Cu and Pd contacts in
60
the catalyst. During the reaction Pd reduces to
metallic form and copper reduces to Cu+. In the
oxygen environment the catalyst regenerates
back to its initial form.
ACKNOWLEDGMENTS
The work was partially supported by Russian
Foundation for Basic Research (projects № 1103-00298, 11-03-00820, 13-03-01003)
REFERENCES
[1] A.A. Chernyshov, A.A. Veligzhanin, Y.V.
Zubavichus, Nucl. Instr. Meth. Phys. Res. A 603
(2009) 95.
[2] I.Yu. Pakharukov, I.E. Bekk, M.M.
Matrosova, V.I. Bukhtiyarov, V.N. Parmon
Dokl. Phys. Chem. V439 (2011) 1, 131-134
61
Pressure-induced phase transitions in the langasite structure
compound Ba3TaFe3Si2O14
P. G. Naumov1,2, I. S. Lyubutin1, V. Ksenofontov2, S. Medvedyev3
and C. Felser3
1
Shubnikov Institute of Crystallography, Russian Academy of Sciences, 119333, Moscow, Russia
2
Max-Planck Institut for Chemie, Mainz, 55020 Germany
3
Anorganische Chemie, Max-Planck-Institut für Chemische Physik fester Stoffe,
01187 Dresden, Germany.
[email protected]
INTRODUCTION
Recently, a great interest was attracted to the
langasite family compounds containing 3d ions
as potential new type of multiferroics. The
langasite La3Ga5SiO14 crystal famous by its
unique piezoelectric properties exceeding quartz
gave the name to the whole family [1]. Among
such
compounds,
the
materials
with
paramagnetic iron, cobalt and manganese ions
A3BM3X2O14 (A = Ba, Sr, Ca, Pb; B = Sb, Nb,
Ta, Te; M = Fe, Co, Mn, X = Si, Ge, P, V, As)
were synthesized [2].
The
magnetic
[2-5]
and
Mössbauer
spectroscopy [6,7] measurements revealed an
antiferromagnetic ordering in a number of these
compounds at temperatures between 7 and 38 K.
Supposed coexistence of electric and magnetic
order parameters in such materials would
provide a creation of a new class of
multiferroics [8,9].
The possible structural phase transitions
initiated by temperature and pressure in the
langasite-family compounds were discussed in
[10]. The change of the trigonal symmetry
(space group P321) to monoclinic (space group
A2-C2) was found in La3SbZn3Ge2O14 with
lowering temperature and in La3Nb0.5Ga5.5O14
and La3Ta0.5Ga5.5O14 under high pressure.
We present the high-pressure X-ray diffraction
and Mössbauer spectroscopy studies of
structural properties of the Ba3TaFe3Si2O14
compound.
X-ray diffraction data
High-pressure X-ray powder diffraction studies
of Ba3Ta57Fe3Si2O14 were performed at the
beamline BL01C of National Synchrotron
Radiation Research Center (NSRRC, Taiwan) at
photon energy 22 keV (λ=0.564 Å). The powder
sample was loaded in in diamond anvil (500 µ
culet size) cell (DAC) with silicon oil as
pressure transmitting medium. A standard ruby
fluorescence technique was used to measure
pressure.
Pressure evolution of X-ray diffraction patterns
of Ba3Ta57Fe3Si2O14 is shown in Fig. 1.
Diffraction patterns at low pressures can be
unambiguously assigned to known trigonal
langasite crystal structure with lattice
parameters a = 8.54 Å, c = 5.24 Å at 0.5 GPa.
This structure remains stable up to P = 18.4 GPa
at which splitting of diffraction lines (e. g. at
2 4.3°) indicates a phase transition to highpressure phase tentatively indexed with
monoclinic unit cell. No further phase
transitions are observed up to the highest
experimental pressure 37 GPa.
62
accordance with
structural studies.
results
of
high-pressure
Fig. 1. X-ray patterns of Ba3Ta57Fe3Si2O14
recorded at ambient pressure and at P = 18 and
37GPa.
Fig. 2. Pressure dependences of the quadrupole
splitting parameter in Ba3Ta57Fe3Si2O14. Solid
lines are guide for eyes.
Mössbauer spectroscopy data
At room temperature and ambient pressure the
Mössbauer spectra of Ba3Ta57Fe3Si2O14 are split
by the electric quadrupole interaction into a
doublet with narrow symmetrical lines. The
quadrupole splitting parameter is ΔE = 1.255 ±
0.005 mm/s, which is very high for Fe3+ ions.
This indicates that the oxygen tetrahedrons with
iron ions are essentially distorted. The isomer
shifts value is  = 0.23 ± 0.1 mm/s (relative to
metallic α-Fe) which supports the ferric iron
state.
ΔE value shows non-monotonous behaviour
with pressure increase. At pressures below 5
GPa value of ΔE remains almost unchanged
followed by rapid value decrease to about 0.85
mm/s at further pressure increase up to 7 GPa
(Fig. 2). The origin of this decrease is
apparently the pressure induced symmetrisation
of local crystal field of Fe+3 ions.
At further pressure increase at P < 18 GPa, the
ΔE value remains almost stable at the level of
0.85 ± 0.03 mm/s. At pressure above 20 GPa ΔE
suddenly increases with subsequent gradual
increase reaching the value of about 1.3 mm/s at
highest experimental pressure P = 30 GPa. The
high pressure behaviour indicates of the
quadrupole splitting parameter indicates
structural phase transition in Ba3Ta57Fe3Si2O14
occurring at pressure above 18 GPa in
CONCLUSION
The high-pressure X-ray diffraction and
Mössbauer spectroscopy measurements were
performed in the iron containing langasire
family compound Ba3Ta57Fe3Si2O14 in diamond
anvil cells. The structural transition were found
by all these methods at pressure of about 18–30
GPa.
ACKNOWLEDGMENT
We deeply thank Dr. B.V. Mill for his help in
the synthesis the Ba3TaFe3Si2O14 sample with
57
Fe isotope. This work is supported by the
Russian Foundation for Basic Research (grants
13-02-12419-ofi-m and 11-02-00636-а) and by
RAS programs “Strongly correlated electron
systems”.
REFERENCES
[1] B. V. Mill, E. L. Belokoneva, and T.
Fukuda, Russian J. Inorg. Chem. 43, 1168
(1998).
[2] B. A. Maksimov, V. N. Molchanov, B. V.
Mill, E. L. Belokoneva, M. K. Rabadanov, A.
A. Pugacheva, Y. V. Pisarevsky, V. I. Simonov,
Crystallography Reports 50, 751 (2005).
[3] K. Marty, V. Simonet, E. Ressouche, R.
Ballou, P. Lejay, P. Bordet, Phys. Rev. Lett.
101, 247201 (2008).
63
[4] V. Yu. Ivanov, A. A. Mukhin, A. S.
Prokhorov, B. V. Mill, Solid State Phenomena
152-153, 299 (2009).
[5] K. Marty, V. Simonet, P. Bordet, R. Ballou,
P. Lejay, O. Isnard, E. Ressouche, F. Bourdarot,
P. Bonville, J. Magn. Magn. Mater. 321, 1778
(2009).
[6] I.S. Lyubutin, P.G. Naumov, B.V. Mill’,
Euro Phys. Lett. 90, 67005(1–6) (2010).
[7] I.S. Lyubutin, P.G. Naumov, B.V. Mill’ ,
K.V. Frolov, and E.I. Demikhov, Phys. Rev. B
84 (2011) 214425 (1–7).
[8] S.A. Pikin and I.S. Lyubutin, Phys. Rev. B,
86 #6 (2012) 064414.
[9] S.A. Pikin and I.S. Lyubutin, JETP Lett. 96,
#4 (2012) 240–244.
[10] B. V. Mill, B. A. Maksimov,
Yu. V. Pisarevsky, N. P. Daniliva,
A. Pavlovska, S. Werner, and J. Schneider,
Crystallography Reports 49, 60 (2004)
64
Grafted Polylactide particles and their Repulsive Forces
Robertus Wahyu N. Nugroho, Torbjörn Pettersson, Karin Odelius,
Anders Höglund, and Ann-Christine Albertsson
Department of Fibre and Polymer Technology, KTH Royal Institute of Technology,
SE-10044 Stockholm, Sweden
[email protected]
ABSTRACT
Agglomeration is a primary problem for small
particles in the range of several tenths of
nanometers to hundreds micrometers. This
physical behavior reduces the particles
numerous advantages for a wide range of
applications. One way to prevent this problem is
to graft hydrophilic polymer chains onto the
surface of the particles, thus resulting in
sterically stabile particles. There are numerous
methods by which the surface modification can
be attained, such as by a ‘grafting-from’
technique under UV-irradiation.
In this work, polylactide (PLA) particles were
surface grafted under UV-irradiation with the
hydrophilic monomers: acrylic acid (AA),
acrylamide (AAm), and maleic anhydride
(MAH). The ‘grafting-from’ technique was
initially developed and shown to be
nondestructive for PLA particles with different
geometries. The change in surface chemistry of
the PLA particles, as confirmed by X-Ray
Photoelectron Spectroscopy (XPS) and Fourier
Transform Infra-Red (FTIR), indicated the
success of surface grafting technique.
Force interaction between two grafted PLA
substrates was measured by colloidal probe
Atomic Force Microscope (AFM) in salt
solutions with different concentrations to
investigate repulsive forces due to steric
stabilization. In order to evaluate force
interaction, AFM force profiles were compared
to the Alexander de Gennes (AdG) model and
Derjaguin-Landau-Verwey-Overbeek (DLVO)
theory. Repulsive forces were mainly detected
in a long range interaction when hydrophilic
polymers were covalently attached to the
particles surface. On the contrary, attractive
forces dominated the interaction when neat PLA
particles approaching each other to agglomerate,
even though short range repulsion was detected
at small separation distance. The surface grafted
particles can be used in biomedical field, e.g.
drug delivery research to overcome particle
aggregation.
Keywords:
Surface modification, AFM,
hydrophilic polymers, steric stabilization,
polylactide, acrylic acid, acrylamide, maleic
anhydride.
ACKNOWLEDGEMENTS
The ERC Advanced Grant, PARADIGM (Grant
agreement no: 246776) for financial support for
this work.
REFERENCES
1. Nugroho, R.W.N., Odelius, K., Höglund, A.,
Albertsson, A.-C., ACS Appl. Mater. Interfaces
2012, 4, 2978–2984.
2. Nugroho, R.W.N., Pettersson, T., Odelius, K.,
Höglund, A., Albertsson, A.-C., Langmuir 2013,
29, 8873–8881.
65
The reaction of decomposition of MnB2H8
Pankin Ilya1, Guda Alexander 1, Filinchuk Yaroslav 2, Soldatov
Alexander 1
1
Nonoscale structure of matter, Southern Federal University, Sorge 5, Rostov-on-Don, Russia.
2
Institute of Condensed Matter and Nanosciences,
UniversitéCatholique de Louvain, Place L. Pasteur 1, B-1348, Louvain-la-Neuve, Belgium
E-mail: [email protected] web: http://www.nano.sfedu.ru
The object of study is borohydride of
manganese MnB2H8. This compound is a solid
state hydrogen storage system. However the
complete desorption of hydrogen destroys of
initial material. Thus further use of this
accumulator of hydrogen becomes not possible.
The main purpose of this investigation is
determination of possible reaction products
decomposition process of initial material to
study process of degradation.
INTRODUCTION
Due to the limited and non-renewable of
conventional
energy source humankind is
interested in the search for alternative sources of
energy e.g. hydrogen energetic. However the
problem of storage of hydrogen fuel is not
solved. The possible solutions to the problem —
the use of solid-state hydrogen storage systems
based on alanates and borohydrides of alkali and
rare-earth metal. In our study we use
borohydride of manganese MnB2H8. Due to its
unique
thermodynamic
properties
and
possibility of in-sity measurement of Mn Kedge XANES spectra (in contrast to light
elements such as Li or Mg) this compound has a
great prospects.
APPROACH
The conventional method which used for
determination of structure of crystal and other
solid-state matter is X-ray diffraction (XRD).
But in our case initial material was degraded in
the process of reaction of decomposition which
was induced by heating the sample.
XRD shows that with increasing temperature
sample loses periodical crystal structure. To
determine the chemical composition and
structure of reaction products we used XANES
(X-ray absorption near edge structure) analysis.
This method of spectroscopy is very sensitive
both to the electronic state of absorbing atom
and to its local environment. So it allows us
investigate the local structure of nanoparticles,
amorphous and bio-samples. t XANES
experimental spectra indicate on phase transition
which is observed by heating sample. Two
different theoretical methods were used for
modeling of XANES spectra. Both are
implemented in the software package FDMnes.
First is based on full multiple scattering theory
and muffin-tin approximation.
The basis
approximation lies in the potential in which the
potential is assumed to be spherically symmetric
in the muffin tin region and constant in the
intermediate region. However for unknown
compound muffin-tin approximation failed to
reproduce the XANES spectrum and timeconsuming Finite Difference Methods (FDM) to
was used instead which allows to avoid muffintin approximation. However in our both ways
bring to similar result.
RESULT AND DISCUSSION
Firstly we have reproduced the spectra of initial
compound to assess the acceptability of
theoretical
methods.
Figure
1
shows
experimental spectrum for initial compound
MnB2H8 corrected on self-absorption. The
curves under experimental spectrum represent
theoretical simulations for different inequivalent
positions of Mn. Therefore spectra calculated
for different absorption atom were summed with
weights corresponding concentration of non-
66
equivalent manganese atoms in the unit cell Mn1
and Mn2.
time the EXAFS data analysis is in progress. In
the future we plan to use the technique of
molecular dynamic.
0,5
2/3Mn1+1/3Mn2
Mn2
0,0
Mn1
-0,5
6500
6550
6600
6650
6700
XANES (rel. units)
XANES (rel. units)
exp. at T=30C (SA)
-1,0
1
Mn3B4(Mn )
2
Mn3B4(Mn )
MnB
0,0
MnB2
-0,5
MnB4
-1,0
-1,5
6550
6600
6650
Energy (eV)
Figure 1
From stoichiometry of initial compound as a
first model were calculated spectra for diboride
of manganese MnB2 (Figure 2). Figure 2 shows
experimental Mn K-edge XANES spectrum
after sample was heated up to 140 degrees.
1,0
0,8
0,6
0,4
MnB2H8 at 140 C (SA)
0,2
Mn2B
0,5
Energy (eV)
XANES (rel. units)
MnB2H8at T=140C (SA)
1,0
1,0
FDM
GREEN
Figure 3
CONCLUSIONS
Mn K-egde XANES spectra were measured in
situ during heating process of MnB2H8 in
vacuum and hydrogen atmosphere. At 110
degrees diffraction patterns disappear and
sample decomposition occurs. From theoretical
analysis of XANES spectra we conclude that
possible reaction products of decomposition
process has local Mn structure similar to
mixture of MnB, Mn2B and MnB4 while
formation of MnB2 and Mn3B4 in the process of
reaction are excluded.
0,0
6500
6600
6700
Energy (eV)
Figure 2
As we see the theoretical spectra does not
satisfactorily describes experimental curve —
thus another manganese boride compounds
should be taken into account. The result of
modeling are shown in Figure 3. The spectra
calculated for MnB, Mn2B and MnB4 in a good
agreement with experimental data. Due this fact
we can consider this compounds as a possible
product the reaction of decomposition. However
for more precise estimation we must use
complementary methods of analysis. At present
REFERENCES
[1] Bugaev A.L., Guda A.A., Dmitriev V.P.,
Lomachenko K.A., Pankin I.A., Smolentsev
N.Yu., Soldatov M.A.,Soldatov A.V. Operando
dynamics of the nanoscale atomic and electronic
structure of materials for hydrogen storage,
Engineering Journal of Don, 4–1 (2012)
[2] Filinchuk Y., Richter B., Jensen T.R.,
Dmitriev V., Chenryshov D., Hagemann H.
Angew. Chem. Int. Ed. 2011. V. 50. No 47. P.
11162–166.
67
Mössbauer study of the FeSeTe compound system
Perunov I.V. 1, Frolov K.V.1, Vasyukov D.M.1,Lyubutin I.S.1,
Korotkov N.Yu.1, Belikov V.V.2, Kasakov S.M.2, Antipov E.V.2
1
Shubnikov Institute of Crystallography RAS, Moscow, Russia, 2 Lomonosov Moscow State University,
Moscow, Russia
[email protected]
INTRODUCTION
The recent discovery of superconductivity in the
iron-based pnictides and chalcogenides has
generated considerable research interest and
initiated a new discussion about possible
magnetic mechanisms of the high temperature
superconductivity1,3,4. The FeSeTe compounds
are considered as a structural simplest
compound system. Fe-based chalcogenides
demonstrates high values of critical current and
critical field Hc2. The remarkable fact is that
FeSe compound undergoes superconducting
transition at low temperatures while FeTe
reveals antiferromagnetic ordering below 70 K.
The investigations of structural, electron and
spin states of Fe ions allow getting new
important
information
about
possible
mechanisms
of
formation
of
the
superconducting state.
Our investigation of the samples of FeSeTe
compound at 295-5 K temperatures yielded the
next results. Mossbauer spectra at 295 K have
paramagnetic shape, magnetic ordering is not
observed. We reveal small magnetic ordering at
the temperatures below critical one for the
purest samples (FeSe0.5Te0.5, FeSe0.2Te0.8). The
comparison of Mossbauer spectra of
superconducting FeSeTe compound and nonsuperconducting Fe1+xTe showed that with
increasing of portion of Te in FeSeTe system
there’s no rise of magnetic ordering. This fact
points out on probable crucial role of interplanar
ions of Fe which may cause strong magnetic
ordering.
In our work we pursued two main purposes.
First of all was to investigate structural, electron
and spin states of Fe ions. Second goal was to
studying of correlation between magnetic
ordering of Fe ions and superconductivity.
APPROACH
We chose the absorption 57Fe Mossbauer
spectroscopy as a method of investigation. The
samples were synthesized by solid-state reaction
process, phase composition were under control
via x-ray methods2. As a result the majority of
the samples were multiphased. We chose the
purest samples for low temperature experiments.
ACKNOWLEDGMENTS
This present work was supported by Russian Fund
of Fundamental Investigations (grants № 10-0300681 and № 11-02-00636) and Project of Departure
of Physical Sciences «Strongly correlated systems».
REFERENCES
1. Kamihara Y. et al. Iron-Based Layered
Superconductor La[O1-xFx]FeAs (x=0.05-0.12) with
Tc=26 K. J. Am. Chem. Soc. 130,3296-3297(2008).
2. Kasakov S.M. et al. A-site substitution in Fe1.1Te:
synthesis,
structure
and
properties.
Chem.Met.Alloys //3,155-160 (2010).
3. Mizuguchi Y., Takano Y. J. Review of Fe
Chalcogenides
as
the
Simplest
Fe-Based
superconductor. J. Phys.Soc. Jpn.
Vol. 79,
10.102001(2010).
4. Shermadini Z. et al. Coexistence of Magnetism
and Superconductivity. In the Iron-Based Compound
Cs0.8(FeSe0.98)2. Phys.Rev.Lett. 106,117602(2011).
68
Study of nanostructural organization of animal hair biological
fiber with X-ray diffraction methods using synchrotron radiation
A.Yu. Gruzinov1, A.A. Vasilyeva2 G.S. Peters1, V.V. Stepanova2
I.A. Staroselskiy1,3 A.V. Zabelin1,2, A.G. Malygin4 A.A. Vazina1,2
1
2
RRC “Kurchatov Institute”, Moscow, Russia,
Institute of Theoretical and Experimental Biophysics RAS, Puschino, Russia,
3
Lomonosov Moscow State University,
4
Bach Institute of Biochemistry RAS, Moscow, Russia
[email protected];
STATEMENT OF OBJECTIVE
The science of tissue structural biology is just
starting, and conceptual and instrumental
approaches for studying the structural biology of
tissue are only going to be developed.
X-ray diffraction patterns of various native
tissues are of fibrillar type and can be attributed
only to a few archetypes of diffraction patterns.
The characteristic features of small-angle X-ray
patterns are determined by the structure of
major fibrillar cytoskeletal proteins, such as
keratin, actin, myosin, tubulin etc., and
extracellular matrix of the fibrous protein
collagen and proteoglycan structures. Our
previous analysis of diffraction patterns of
native epithelial tissues reveals their similarity
to the diffraction patterns of mucus [1, 2, 3].
The similarity of diffraction patterns of
epithelial tissue and mucus allows to combine
them into a completely new archetype of smallangle X-ray patterns, characteristic feature of
which is presence of multiple Bragg reflexes of
the Debye type with a major period 4.5 nm.
As a model hair tissue (keratinized epithelial
tissue) was chosen because it has a rich fibrillar
type diffraction pattern, which is characterized
by translational symmetry in two directions —
lateral and axial.
METHODS AND OBJECTS OF STUDY
X-ray diffraction experiments were performed
on the small-angle diffraction station DICSI [4]
stated on the storage ring "Siberia-2" (RRC
"Kurchatov Institute", Moscow) at λ = 0.162
nm. Semiconductor CCD-matrix (MAR CCD),
being cooled to -80 degrees, was used as a
detector. Typical exposure times were 1-5
minutes, beam current = 70–100 mA. Standard
diffraction patterns of silver behenate powder
and samples of moist collagen from rat tail
tendon were taken to calibrate the scale of
scattering angles.
Collections of the animal hair used in the
hair studies:
Collection 1 — several hundred samples of
different species of animals (mice, rats, dogs)
from the animal house of the FIB Chelyabinsk40. These animals varied in age, sex, feeding
and housing conditions.
Collection 2 — mice from the Bach Institute of
Biochemistry RAS (Prof. A.G. Malygin), which
consisted of about 300 individuals, the
descendants of normal females and males with
an inherited mutation producing a dwarf
phenotype. The criteria for mutations were body
weight, growth retardation, life expectancy and
mortality rate [5]);
Collection 3 — rats of two age groups and
housed in two different animal houses with
significantly different conditions.
Diffraction patterns from tissues of animals of
these different collections show the presence of
cytoskeleton (keratin) fibrillar structures as well
as
extracellular
matrix
(proteoglycan).
Comparative analysis of the diffraction patterns
shows considerable variation in diffraction line
parameters and diffuse small-angle scattering,
the intensity and symmetry of which was
changed from radial and ellipsoidal to
hexagonal.
69
A preliminary conclusion from the comparative
analysis is that the diffraction patterns of the
mutants are characterized by a multitude of
reflections produced by keratin fibrils (fig. 1, b).
The diffraction patterns of samples of normal
mice are significantly different from those of
mutants and are more similar to the patterns
from collection 1 samples, which have much
fewer reflexes, poor intensity and contrast (fig.
1, a). This phenomenon can be attributed to the
flexibility of keratin fibrils, resulting in a change
of the chain conformation.
It can be noted that in the diffraction patterns of
normal mice, as well as rats and mice from
collections 1 and 3, Bragg reflections of Debye
type with 4.5 nm period are registered, which
can be attributed to the presence of proteoglycan
fibrils (fig. 1, а).
Fig. 1. Small-angle diffraction patterns of mice
hair tissue — normal (a) and mutant (b).
Diffraction patterns of mutant mice (b) have a
clear set of meridional reflections attributed to
supercoiling α-helical bundles packed in keratin
intermediate filaments, which is the most
intense reflex with 6.7 nm period a seventh
order of the major 47 nm period. Diffraction
pattern of samples of normal mice from
collection 2 (a), which differ significantly from
those described above, are similar to the patterns
of control samples from collection 1
The role of element composition in the
nanostructural
transformation
of
the
extracellular matrix consisting of proteoglycan
fibrils is currently being discussed. A
mechanism of conformational lability of
proteoglycan structures in the modifying
adaptation of biological tissues to endogenous
and exogenous influences is proposed. Our
nanostructural studies of hair and fur tissues of
animals allow raising the fundamental question
of biophysics about the interdependence of
“structure and function”. Hair tissue of animals
in poor physiological state give a clearer smallangle diffraction pattern than tissue of healthy
animals living in good conditions, which have a
bigger adaptation potential to endogenous and
exogenous influences.
The obtained results of nanostructural research
of biological tissues using synchrotron radiation
can be applied to identification of
morphological markers suitable for monitoring
of the physiological state of tissues.
REFERENCES
1. Aksirov A.M., Vazina A.A. et al., Biological
and medical application of SR from the storage
rings of VEPP-3 and “Siberia-2”. The origin of
specific changes of small-angle X-ray
diffraction pattern of hair and their correlation
with the elemental content, Nucl. Instr. Meth. in
Phys. Res., 2001, vol. A470, p. 380-387.
2. Vazina A.A., Bras A.Yu. et al., Peculiarities
of human hair structural dynamics, Nucl. Instr.
Meth. in Phys. Res., 2005, vol. A543, p. 153157.
3. Vazina A.A., Budantsev, A.Yu., Bras et al.,
X-ray diffraction and spectral studies of
biological native and modified tissues, Nucl.
Instr. Meth. in Phys. Res., 2005, vol. A543, p.
297-301.
4. Ariskin N.I., Gerasimov V.S., Korneev V.N.,
Stankevich V.G., Vazina A.A. et al., System of
primary collimators of SR beam at the smallangle station for KSRS, Nucl. Instr. Meth. in
Phys. Res., 2001, vol. A470, p. 118-121.
5. Malygin A.G. Variations of mice life duration
concerning processes of their increasing and
ageing. Moscow Society of Naturalists
conferences, Gerontology section, 2012, vol. 50,
pp. 56-65.
70
Prefocussing at PETRA II Beamline P06
S. Ritter1, S. Hönig1, C. Baumbach1, J. Patommel1, M. Kahnt1, D.
Samberg1, R. Hoppe1, F. Seiboth1, J. Reinhardt2, U. Bösenberg2,
N. Reimers2, G. Wellenreuther2, G. Falkenberg2
and C. G. Schroer1
[1] Institut für Strukturphysik, TU Dresden, D-01062 Dresden, Germany
[2] HASYLAB@DESY, Notkestr. 85, D-22607 Hamburg, Germany
[email protected]
INTRODUCTION
Hard x-ray microscopy is a powerful method to
image structure of small objects. Microscopic
setup at PETRA III beamline P06 [1] provides
access to different contrast mechanisms such as
absorption spectroscopy, fluorescence and
(coherent) diffraction. The Beamline is designed
to produce hard x-ray beams with sizes of 50
nm (FWHM) and even smaller. Ptychography
[2] improves the resolution to below 10 nm for
radiation hard samples. A higher flux at the
sample can be achieved with prefocusing. It
results in shorter exposure times and a better
resolution in time and space. For characterize
the prefocusing ptychographic scanning
coherent diﬀraction imaging technique is used.
RESULTS AND CONCLUSIONS
The measurements results weak or no
prefocusing leads to high degree of coherence
and a low flux in focus. If prefocusing matches
transverse coherence length lt to aperture of
microscope optic, one capture the available
coherent flux and gain high flux. With this setup
coherence decreases as the coherent focus size.
In addition the Prefocus secondary source
shortly before microscope optic creates high
flux but a larger incoherent focus.
For all that our experiment shows the
ptychographic
reconstruction
[2]
with
prefocusing is still possible.
In conclusion the theoretical predicts could be
confirmed almost. The Beamline P06 at PETRA
III provides 2D mapping and 3D scanning
tomography,
contrast
mechanisms
like
fluorescence or transmission and prefocussing.
In the energy range from 10 to 30 keV an
resolution between 500 nm and 50 nm. or below
with refractive optics [3,4] is feasible.
ACKNOWLEDGMENT
The authors thank the Beamline stuff for their
excellent technical support. The experiments at
DESY were carried out as part of the
commissioning of Beamline P06 at PETRA III.
This work was supported by the BMBF.
REFERENCES
[1] C. G. Schroer, et al. „Hard X-ray nanoprobe
at beamline P06 at PETRA III“ Nucl. Instrum.
Methods A, 616, (2009)
[2] A. Schropp, et al. „Hard X-Ray Nanobeam
Characterization by Coherent Diffraction
Microscopy“ Appl. Phys. Lett., 96, (2010)
[3] J. Patommel, „Hard X-Ray Scanning
Microscope Using Nanofocusing Parabolic
Refractive Lenses“, (2010)
[4] C. G. Schroer, et al. „Hard x-ray nanoprobe
based on refractive x-ray lenses“ Appl. Phys.
Lett., 87, (2005)
71
High-Resolution Chemical Imaging of Gold Nanoparticles Using
Hard X-Ray Ptychography
Juliane Reinhardt(1*,2), Robert Hoppe(2), Georg Hofmann(3),
Christian D. Damsgaard(4), Dirk Samberg(2), Jens Patommel(2),
Gerald Falkenberg(1), Gerd Wellenreuther(1), Preety Bhargava(1),
Jan-Dierk Grunwaldt(3) and Christian G. Schroer(2)
(1)
(2)
DESY Notkestraße 85, D-22607 Hamburg, Germany,
TU Dresden, Institute of Structural Physics, D-01062 Dresden, Germany,
(3)
Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany,
(4)
Technical University of Denmark, DK-2800 Kgs Lyngby, Denmark
[email protected]
INTRODUCTION
Probing catalysts during their preparation,
activation, and under operating conditions is of
great importance for a better understanding and
systematic advancements of catalytic reactions
[1]. By recording a series of ptychograms at
different energies around an absorption edge of
an element of interest, the near-edge structure
information in terms of absorption and phase
shift can be obtained with the same high spatial
resolution as seen in the ptychographic
reconstruction.
The phase shift is quantitively related to the
energy-dependent refractive index, which is
element specific and also sensitive to the
oxidation state and the local chemical
environment around an atomic species. As the
refraction data has a better signal-to-noise ratio
than the absorption for small objects, it is
advantageous for chemical nano imaging to
make use of the resonant dispersion to evaluate
the chemical state of the element of interest.
APPROACH
In ptychography the sample is scanned through
a coherent nanofocused beam (≈ 100 nm
FWHM), recording a far-field diffraction pattern
at each position of the scan. An appropriate
overlap between the illumination at adjacent
scan points allows for the unambiguous
reconstruction of the complex transmission
function of the object by numerical phase
retrieval algorithms [2,3]. For this particular
experiment we used nanofocusing parabolic
refractive x-ray lenses [4,5].
As proof of principles, we measured a simple
model sample. This sample contains gold
nanoparticles with a diameter of about 100 nm.
A platinum ring serves as marker and reference.
The material is located on a Si3N4 membrane
window of a TEM grid.
RESULTS & DISCUSSION
We locally evaluated the phase shift of
ptychograms of different energies at the Au-L3
edge. The resonant dispersion is seen for the
gold particles in terms of a decrease in the
negative phase shift. The phase shift of platinum
remains constant, Fig. 1.
72
Fig.1 Phase shift of gold and platinum at the
Au-L3 edge and a reference absorption
spectrum. The negative phase shift decrease is
also shown in phase reconstructions at selected
energies.
Based on the Kramers-Kronig-Relation it is
possible to calculate the phase shift from
absorption reference data and compare these
values to the phase shift in the ptychographic
reconstructions.
Spatial Resolution
The sample geometry is known. Therefore the
resolution was determined by comparing
simulated gaussian-blurred spheres with the
ptychographic reconstruction.
The local resolution is about 20 nm.
CONCLUSIONS & OUTLOOK
It was shown, that it is possible to obtain
chemical
information
from
resonant
ptychography with a spatial resolution of 20 nm.
The maximum resolution depends on the
scattering intensity in high scattering angles.
Strong scattering features are advantageous. To
improve the spatial resolution a high incident
flux is required. Therefore prefocusing will be
used in the future. To increase the accurancy of
the phase shift values a better signal-to-noise
ratio has to be achieved by using beamstops.
Resonant scanning coherent diffraction imaging
has significant advantages over conventional xray
scanning
microscopy,
e.g.,
with
transmission or fluorescence contrast. The
spatial resolution is unaffected, independent of
the chromaticity of the optics [6].
The long-term aim is to investigate nano
particles in heterogeneous catalysts in-operando.
ACKNOWLEDGMENT
The authors thank P. Bhargava, N. Reimers, B.
de Samber (DESY), D. Samberg (TU Dresden),
A. Fuller, and J. B. Wagner (DTU) for their
technical support. This work was supported by
the German Ministry of Education and Research
(BMBF) under Grant Nos. 05K10OD1 and
05K10VK1 and by VH-VI-403 of the Impulsund Vernetzungsfonds (IVF) of the Helmholtz
Association of German Research Centres. G.H.
was supported by the Helmholtz-Kolleg
“Energy Related Catalysis”. Beamtime at
beamline P06 at PETRA III was granted within
the in-house program of DESY. Gold references
were measured at beamline microXAS at
synchrotron radiation source SLS at PSI.
REFERENCES
[1] J.-D. Grunwaldt and C.G. Schroer, Chem.
Soc. Rev. 39, 4741 (2010)
[2] P. Thibault et al., Ultramicroscopy 109, 338
(2009).
[3] A.M. Maiden, J.M. Rodenburg, Ultramicroscopy 109, 1256 (2009).
[4] C.G. Schoer, et al., Appl. Phys. Lett. 82 (9),
1485 (2003).
[5] C.G. Schroer et al., Appl. phy. Lett. 87 (12),
124103 (2005).
[6] R. Hoppe et al., Appl. Phys. Lett. 102,
203104 (2013).
73
Application of XAFS for study Cu, Zn in soil
Podkovyrina Yu.S. 1, Soldatov A.V.1, Nevidomskaya D.G.2,
Minkina T.M.3
1
Southern Federal University, Facultyof Physics, Physics of nanosystems and spectroscopy Department,
040, 5, Sorge st., Rostov-on-Don, 344090, Russia,
2
Institute of Arid Zones of the Southern Scientific Centre RAS, 41,
Chekhov st., Rostov-on-Don, 344006 Russia,
3
Southern Federal University, Faculty of Biology, Soil Science Department, 813, 194/1, prosp. Stachki,
Rostov-on-Don, 344090, Russia
[email protected]
INTRODUCTION
At present, the growth of industrial production
has a major influence on environment pollution.
In particular, the soils near the industrial plants
are susceptible to contamination by heavy
metals. Heavy metals (TM) — are
biochemically active technogenic substances
that affect on living organisms. In natural
conditions, most of these metals are essential
trace elements for plants and animals. A toxic
effect of TM is shown with an increase in
concentration limit. Metals can accumulate in
plants and organisms and transmitted in
increasing quantities on the food chain.
Mercury, zinc, lead, cadmium, arsenic are
especially hazardous, since they penetrating
with food in humans and higher animals can
cause poisoning. The study of contaminated
soils is reduced not only to the determination of
the concentration of TM, but also identifying the
type of compounds (mobile or stable) which the
metal could form. X-ray techniques have played
a crucial role in finding the answers to many
questions related to biology and environment
sciences [1]. Study of the extended fine
structure of the X-ray absorption spectra
(EXAFS) allows to obtain the information about
metal-bearing soil phases and to distinguish the
interaction type between the metal ions and soil
components. In XANES region photoelectrons
have a free path (without collision with
neighboring atoms), which is longer than in
EXAFS region, thus by a multiple scattering
process on the surrounding atoms it is possible
to determine the 3D atomic structure of metal
ion local environment. Moreover XANES
provides information on an oxidation state of an
absorbing atom. A combination of both the
experimental investigations and the «first
principle» calculations was proved as
particularly effective [2].
APPROACH
Samples. The samples of soil components
(calcite, kaolinite, bentonite, preparations of
humic acids isolated from ordinary chernozem)
were saturated by Zn2+ and Cu2+ ions. The
studied samples were placed in a saturated
solution of Cu2+ and Zn2+ nitrates. The solution
was changed twice a day during a week. The
constant level of pH was maintained. One week
later, the samples were extracted from the
solution and dried. The incubation period of
metals in soils and soil components lasted for
one year. Experimental and theoretical data. The
experimental XANES spectra at the Zn K-edge
(9659 eV) and the Cu K-edge (8979 eV) were
measured by the laboratory spectrometer Rigaku
R-XAS Looper. The data were obtained in the
fluorescence mode. Due to the low Cu
concentration in the sample of humic acid,
which was recovered from an ordinary
chernozem, the experimental XANES spectra at
the Cu K-edge were recorded at Kurchatov
synchrotron radiation source. The calculations
were performed using both the finite difference
method in full potential FDMNES 2012 [3] and
self- consistent method of full multiple
scattering in the muffin-tin approximation for
the potential FEFF9.54 [4].
74
The morphology, size, and peculiarities of edge
and near-edge areas on XANES spectra of soil
samples contaminated by CuO and Cu(NO3)2
have clear differences mainly controlled by the
differences in their local atomic structure around
the central Cu ion. The spectra of soil samples
contaminated by CuO demonstrate close
similarity to experimental spectra of the initial
copper-bearing compound CuO. By contrast, the
spectra of soils treated by Cu(NO3)2 differ
significantly from the spectra of the initial
copper-bearing compound providing evidence
for transformation of the environment of the
copper ion introduced into the soil. Copper
nitrate is well-soluble in water (pK Cu(NO3)2 =
0,40, pK CuO = — 7,66), because of this,
copper ions during the one year of incubation
were sorbed by the soil and formed various
compounds,
including
organo-metallic
complexes with different functional groups [5].
Analysis of the Zn K-edge XANES spectra for a
carbonates soil phase showed that the Zn ions
could replace the Ca ions in the octahedral sites,
representing the 1s→4p transition. Moreover,
they coordinate with Ca ions as ligands, forming
an adsorbed complexes on a surface in defects
and broken-edge sites. The experimental Cu Kedge XANES spectra for humic acid and
Cu(NO3)2 are differs. The intensity of «white
line» in the copper nitrate spectrum higher than
in the humic acid spectrum. It is observed, that
humic acid XANES spectra is broader than
spectrum of reference compound. Should be
noted that the first derivatives of the Cu XANES
spectra reveal more detailed information and
show obvious splitting of the and peaks in the
edge region. Thus, it suggests that a weak
shoulder structure exists in XANES spectra. It
is mean that Cu-O and Cu-N distances changed.
This fact allows to make a conclusion that
octahedral Cu binding sites are tetragonallydistorted. The distortions may occur due to the
ion exchange with humic acid functional groups
and water molecules. They cannot be caused by
the Jahn-Teller effect because it occurs only
when all ligands are identical. The outer-sphere
unstable complexes are formed by interactions
of Zn2+ ions with functional groups and ligands
of humic acid. This result is confirmed with
dates of fractionation and previously received
results [6]. The research has shown that
increasing soil contamination leads to
domination of weakly bounded Zn compounds
in strongly bounded compounds.
CONCLUSIONS
Combining of XANES X-ray absorption
spectroscopy and extractive fractionation is
effective for establishing connections of metallic
ions with soil compounds, as well as identifying
the phases-carriers of metals in soils and their
bonding strength. Humic acids interact with
Zn2+ ions and could form outer-sphere
complexes by interacting with the functional
groups and ligands, while Cu2+ ions form innersphere organometallic complexes. Zn2+ ions
replace Ca2+ ions in the octahedral positions and
form absorption complexes as ligands with the
CO32- ions on the surface of the calcite.
REFERENCES
[1] A. Prange and H. Modrow, “X-ray
absorption spectroscopy and its application in
biological , agricultural and environmental
research,” pp. 259–276, 2003.
[2] Smolentsev G.Y., Soldatov A.V., 2009.
Journal of Surface Investigation: X-Ray,
Synchrotron and Neutron Techniques.Vol.
3.No 3. pp. 398-401.
[3] Bunau O., Joly Y., 2009. J.Phys.:Condens.
Matter , V.21, No.34
[4] Rehr J.J., Kas J.J., Vila F.D. Prange M.P.
Prange, Jorissen K., (2010)
Phys.Chem.Chem.Phys. 12 (21)5503-5513.
[5] Minkina T.M., Soldatov A.V.
Motuzova G.V., PodkovyrinaYu.S.,
Nevidomskaya D.G.,2013b.
Doklady Earth Science. Vol. 449.Part 2. pp.
418-421.
[6] Minkina T. M., Motuzova G. V, Nazarenko
O. G., Mandzhieva S.Group. Eurasian Soil
Science, 2009. Vol. 42, No. 13. pp. 1–10.
75
Phase separation of complex half-doped
154Sm0.32Pr0.18Sr0.5MnO3 manganite
G. Sarapin1,2, A. Kurbakov1,2, V. Ryzhov2, C. Martin3, A. Maignan3
1
Neutron and Synchrotron Department, Physical Faculty, Saint-Petersburg State University, 2B.P.
Konstantinov St. Petersburg Nuclear Physics Institute, National Research Center Kurchatov Institute,
3
Laboratoire CRISMAT, Universite de Caen
[email protected]
Earlier, from researches of Sm0.5Sr0.5MnO3 and
Pr0.5Sr0.5MnO3 compounds were obtained that
the replacement of Sm by Pr or vice versa can
drastically change the magneto-transport
properties of manganites. By methods of
neutron
powder
diffraction,
neutron
depolarization, temperature dependences of
magnetization, its second harmonic and
electrical resistivity was studied the phase
separation and microscopic nature of the
magnetoresistance in Sm0.32Pr0.18Sr0.5MnO3
manganite. Existence of structural phase
transition at 170K from high temperature Pbnm
orthorhombic phase to a mixture of two phases:
orthorhombic Pbnm and monoclinic Р21/m, with
coherently coupled by atomic in the unit cell,
but with different lattice parameters was
revealed.
Analysis of the magnetic contribution indicates
that ground magnetic state is a phase separate
with the mixture of three magnetic phases:
ferromagnetic
(TC
~300К),
A-type
A
antiferromagnetic
(TN
≈
170К)
and
antiferromagnetic charge ordering pseudo-CEtype (TNCE ≈ 120К) arising because of the strong
competition between the mechanisms of
localization and delocalization of charges. F
ordering corresponds to the weakly deformed
high-temperature Pbnm phase. Both AF states
correspond to monoclinic crystal structure,
strongly compressed along c-axis. As a result,
the
microscopic
nature
of
the
magnetoresistance, which is reflected in
decrease the ρ by several orders at applying
magnetic field 7 T is described.
This work was supported by RFBR grant
No. 12-02-00073.
76
Development and characterization of a new magnetic sample
environment for experiments at P10 beamline of
PETRA III facility
Alexander Schavkan1, Fabian Westermeier1, Birgit Fischer1,
Alessandro Ricci1, Martin Schroer1, Gerhard Grübel1,
Michael Sprung1
1
INTRODUCTION
The behavior of nanoparticle systems under
influence of a tunable parameter is a topic of
great interest (“smart nanoparticles”). The goal
is to introduce a controlled macroscopic
response of the nanoparticle system upon a
change of an environmental parameter (e.g.
temperature, pressure, magnetic or electric
fields).
The objective of the experiments
described here was the development and
characterization of a sample environment with
tunable magnetic field.
DESY Deutsches Elektronen-Synchrotron, Hamburg
[email protected]
two electromagnets using crossed yokes (see
Figure 1).
THEORETICAL CALCULATIONS AND
CHOICE OF MATERIALS
Dimensions for a solenoid were estimated using
this design idea. It was decided to manufacture
solenoids with a length of
and a
maximum radius of
. A wire with
radius
was chosen for the solenoid.
The yoke can consist of different materials. The
chosen material for the first prototype was a
HiMu80-alloy by Cartech. This alloy needs only
small field to be activated and offers a large
permeability. The rods available had a diameter
of
defining the minimum
radius of the coil to be
. The
magnetizing force of the solenoid was calculated
by
(1),
Fig. 1: Design of the magnetic insert
APPROACH
The P10 beamline offers a flexible setup to
implement special sample environments. The
sample chamber is based on a DN100 cube with
accessible flanges from 4 sides. Requirements
for the magnetic insert design were given by the
dimensions of the cube and the possibility to
apply magnetic fields parallel and perpendicular
to the beam direction as well as change field
amplitude and direction. The design consists of
where is the current,
is the number of the
loops in the solenoid,
is the length of the
solenoid, is the distance from the end of the coil
to the measurement point (estimated in the middle
of the solenoid) and
are the radii of the
different layer of the coil [1]. The magnetizing
force of a solenoid with
,
and 23 layers was calculated to
, which should provide a saturation
flux density of
in the yoke. The flux
density in the air gap is defined as
77
(2),
where
,
is the length of the
yoke and
is the length of the air gap [1].
According to this equation a magnetic field
strength of
is expected for
.
EXPERIMENTAL RESULTS
The magnetic chamber was built and tested.
The measurements provided the maximum field
strength:
and
Switching on fields in
both directions provided a stronger field with
, which agrees with a
theoretical prediction of a field with
under
Fig. 5: Goethite particles aligned in the field
a) perpendicular and b) parallel to the field
parallel to the beam and
perpendicular to
the beam. Applying a field of the same strength
in both directions provides a field direction
in
respect to the x-ray beam with a strength of
. The strength of the provided field was
enough to align Hematite and the Goethite
particles in a water solvent. The design of the
magnetic sample environment provides new
experimental
opportunities
due
to
the
implemented possibility to apply the magnetic
field parallel to the beam, too. The prototype
showed that the design is working according to
predictions. Further work is planned to improve
the strength of the magnetic field and to provide
fast switching capabilities.
Hematite particles are known to align under the
influence of low magnetic fields starting from
Fig. 2 shows that hematite
particles are aligning horizontally and
perpendicular to the beam for both applied
fields –perpendicular and parallel to the beam,
which results in different images on the detector
and gives the access to the different dimensions
in the investigation of the dynamics[2].
On the other side, Goethite particles are aligning
parallel to the field [3]. This is shown with the
scattering pattern in fig. 3.
REFERENCES
[1] L. Bergmann, C. Schäfer. (2006).
Elektromagnetismus. Walter de Gruyter.
[2] B. J. Lemaire et al. (2005). The complex phase
behaviour of suspensions of goethite (α-FeOOH)
nanorods in a magnetic field. Faraday Discuss.
128
[3] Ch. Märkert et al. (2010). Small angle
scattering from spindle shaped colloidal hematite
particles in external magnetic fields. IUCr
CONCLUSIONS
The calculations show that magnetic field
strength of > 200mT should be possible with the
presented design. The experimental results
demonstrated that at the moment the design can
provide a maximal field strength of
ACKNOWLEDGEMENTS
We want especially recognize the help of Mr.
Bernd Hentschel from MKS group at DESY
during the manufacturing of the coils and Mr.
Kornowski from University Hamburg for the help
during the synthesis of the samples and,
especially,
for
the
TEM
analysis.
Fig. 4: Hematite particles aligned in the field
a) perpendicular and b) parallel to the beam
78
Two ground states in mixed in mixed Mn1-xFexGe compounds
S.-A. Siegfried1, N. M. Potapova2, E. V. Altenbayev2,3,
V.A. Dyadkin4,2, E. V. Moskvin2,3, V. Dimitriev4, D. Menzel5,
C. D. Dewhurst6, D. Chernyshov4, R. A. Sadykov7,8,
L.N. Formicheva7, A. V. Tsvyashchenko7, D. Lott1, A. Schreyer1
and S. V. Grigoriev2,3,
1
Helmholtz Zentrum Geesthacht, Geesthacht 21502, Germany,
Petersburg Nuclear Physics Institute, 188300 Gatchina, Saint-Petersburg, Russia,
3 Saint-Petersburg State University, Ulyanovskaya 1, 198504 Saint-Petersburg, Russia,
4
Swiss-Norwegian Beamlines at the European Synchrotron Radiation Facility, 38000 Grenoble, France,
5
Institut fur Physik der Kondensierten Materie, TU Braunschweig, Braunschweig 38106, Germany,
6
Institute Laue-Langevin, 38042 Grenoble Cedex 9, France,
7
Institute for High Pressure Physics, Russian Academy of Sciences, 142190 Troitsk, Moscow, Russia,
8
Institute for Nuclear Research, Russian Academy of Sciences, 117312 Moscow, Russia
[email protected]
2
perpendicular to the incoming neutron beam.
The samples with a Fe-doping x ≤ 0.4 behave
similar to pure MnGe, while for x > 0.75 it
behaves similar to pure FeGe. For the iron
doping between 0.45 and 0.75 an additional
second state appears.
As example the samples with x = 0.6 will be
discussed in more details. For field scans at low
temperatures a transition from ring-like pattern
(fig.1a) (which indicates the coexistence of
randomly oriented wavevectors k) to a spot-like
pattern with two spots (fig. 1b) in magnetic field
direction (k1 || H) is observed due the
reorientation of the wavevectors along the
external magnetic field direction. The critical
field strength is HC1 ≈ 0.15 T. For further field
increasing the double scattering in field
direction disappears and the remaining peak
broads (fig.1c). In field region between HC1 ≈
0.15 T and HC2 ≈ 0.45 T an intermixed helical
state seems to exist. In this region the helical
structure oscillates between two ground states
with k1 and k2. Above HC2 up to HC3 ≈ 0.6 T the
broadened peak contracts again to one thin peak
(fig.3d) and just one single helix exists with k2.
Finally for fields higher than 0.6 T the helical
structures vanishes and the spin structure
becomes field aligned. In conclusion we have
The cubic B20 monogermanides belong to the
P213 space group. Below Tord pure MnGe and
FeGe order in a one-handed helical structure
with a propagation vector of k ≈ 2.3 nm-1 for
MnGe and k ≈ 0.09 nm-1 for FeGe [1,2,3]. The
magnetic properties of these systems are based
on a hierarchy of different interactions: the
strong ferromagnetic exchange interaction the
Dzyaloshinskii-Moriya (DM) interaction, the
Anisotropic Exchange (AE) and the cubic
anisotropy. The helicity is induced by the DM
exchange interaction, due the lack of symmetry
of the magnetic atoms in these compounds. The
orientation of the spiral is fixed along the
principal interaction in these system by the AE
interaction and the cubic anisotropy [4,5].
Polycrystalline Mn1-xFexGe samples (0.0 ≤ x ≤
1.0) have been synthesized by high pressure
method
[6].
SQUID
magnetization
measurements were used to establish the
magnetic ordering temperature. Tord decreases
from x = 0.0 to x = 0.4 from 140 K to 120 K and
increases linearly to 278 K for further Fe doping
up to 1.0. Small angle neutron scattering
(SANS) measurements were carried out the
instrument D11 at the Institute Laue Langevin
and the SANS-1 at the Meier-Leibnitz-Zentrum
(MLZ). The field geometry was always
79
observed a non-trivial field evolution of the
magnetic structure in the intermixed compounds
Mn1-xFexGe.
While
for
high
Fe/Mn
concentration the compounds behave like pure
FeGe/MnGe, the mean concentration range
(0.45 ≤ x ≤ 0.75) giving rise for a second
magnetic ground state.
[1] N. Kanazawa, et al., Phys. Rev. Lett. 106,
156603 (2011)
[2] O. L. Makarova, et al., Phys. Rev. B. 85,
205205 (2012).
[3] B. Lebech, et al., J. Phys. Condens. Matter
1, 6105 (1989).
[4] I. E. Dzyaloshinskii, Zh. Eksp. Teor. Fiz. 46,
1420 (1964).
[5] P. Bak, M. H. Jensen, J. Phys. C13, L881,
(1981).
[6] A. Tsvyashchenko, et al., Journal of Less
Common Metals 99, 2, L9 (1984).
Figure 1: SANS maps for Mn0.4Fe0.6Ge at 30
K: a) 0 T, b) 0.15 T, c) 0.35 T, d) 0.5 T
80
Study of the temperature dependencies in ferromagnetic
inverted opal-like structures by the SQUID-magnetometry
I.S. Shishkin1, A.A. Mistonov1, N.A. Grigoryeva1, D. Menzel2, K.S.
Napolskii3, N.A. Sapoletova3, A.A. Eliseev3, S.V. Grigoriev1,4
1
Faculty of Physics, Saint Petersburg State University,Russia,2Institut für Physik der Kondensierten
Materie Technische Universität,Germany,3Department of Materials Science, Moscow State
University,Russia,4Petersburg Nuclear Physics Institute, Gatchina,Russia
[email protected]
The investigations of the magnetic properties of
ferromagnetic crystals with the inverted opal
structure by the SQUID-magnetometry were
performed. Temperature dependencies of the
magnetization at the different values of external
magnetic field for structured films based on
nickel and cobalt with different thicknesses
were measured.
INTRODUCTION
Inverse opal-like structure (IOLS) is a
metamaterial, which is producing by the filling
of the voids in template opal structure with
desired material and subsequent removing of the
template. The size and chemical composition of
the IOLS are tunable by varying the size of the
colloids and the infiltration materials,
respectively. IOLS based on ferromagnetic
materials are so interesting, because they can be
presented as three-dimensional nanoscale
analogue of conventional spin ice [1]. Since the
spin ice is characterized by the frustrated states
of magnetic moments, temperature study of the
IOLS magnetic properties is the important
fundamental task. Some experiments have
already been performed in 2011, and it was
shown, that SQUID-magnetometry allows to
obtain information about the total magnetization
behavior in the IOLS as a function of the angle
between the external magnetic field and
sample’s plane.
SAMPLES AND METHODS
Inverse opal-like structures (IOLS) were
fabricated by using electrodeposition technique
and utilizing a colloidal crystal film as a
template [2]. The colloidal crystal film was
prepared by the vertical deposition of
monodisperse
polystyrene
microspheres
(D = 530 ± 10 nm) onto a Si(100) wafer coated
with a 100 nm-thick gold layer [3]. IOLS as
well as the template artificial opal possesses
presumably face-centered cubic (fcc) ordering.
Thus, all the directions in IOLS are strongly
determined. One can consider IO as an assembly
of small metallic particles duplicating the shape
of the voids between the spheres and connected
to each other via thin (several tens of
nanometers) and long (several hundreds of
nanometers) crosspieces (Fig. 1).
Li et al. Angew. Chem.
Int. Ed. 2007, 46
Fig. 1 The base
element of an OLS
Fig. 2 The
experimental setup –
SQUID-magnetometer
Due to this complicated spatial structure, IOLS
possess amazing magnetic properties. Inverse
opal-like structures based on Ni and Co were
studied. For both materials there were several
samples of different thickness – from 0.5 to 26
hexagonal close-packed layers or thickness from
0.25 mkm to 13 mkm. Measurements were
carried out with the SQUID-magnetometer
81
Quantum Design MPMS-5S, which is located at
the Institute Physics of Condensed Matter,
Braunschweig, Germany. The scheme of the
setup is presented in Fig. 2. Temperature
measurements were carried out by the zero-field
cooling (ZFC), field-cooling (FC) procedure,
when the sample is cooling in zero magnetic
field, then heating in some certain field H and
after that cooling again in the same field H. The
values of magnetic field H of 30, 120 and 200
mT were used. Cooling and heating were done
in the temperature range from 3 to 350 K.
Temperature dependencies of the magnetization
for the sample based on nickel with the
thickness of 13 mkm are presented in Fig. 3a.
ZFC 30 mT
FC 30 mT
ZFC 120 mT
FC 120 mT
ZFC 200 mT
FC 200 mT
Magnetization (emu)
0,0200
0,0175
0,0150
0,0125
0,0100
0,0075
a
0,0050
0,0025
0
50
100
150
200
250
300
350
400
Temperature (K)
ZFC 200mT
FC 200mT
ZFC 120mT
FC 120mT
ZFC 30mT
FC 30mT
Magnetization (emu)
0,008
0,006
0,004
0,002
b
0,000
0
50
100
150
200
250
300
350
400
Temperature (K)
Fig. 3 Temperature dependence the sample
based on nickel (26 layers) (a) and on cobalt (11
layers) (b)
One can see, that they have the stepped
character. Each curve has its own rate of change
of the magnetization, since they have different
slope. At low temperatures (3 - 25 K), there is a
feature in the form of magnitude divergence
ZFС and FC curves, which decreases with
increasing magnetic field. On the ZFC curves in
the temperature range 30–55 K the
magnetization «jump» is observed. The
magnitude of this jump decreases with
increasing magnetic field, but its position
remains unchanged at the different fields. For all
value of fields in the temperature range 60 - 225
K, there is a monotonic increase of the
magnetization. For the field of 30 mT in a
temperature range 230-270 K is observed the
plot with decrease of velocity of magnetization.
For fields 120 mT and 200 mT in the same
range of temperatures observed constancy of
values of magnetization. In Fig. 3b the
temperature dependencies of the magnetization
for the sample based on cobalt with the
thickness of 5.5 mkm are presented. Like in case
of the Ni-based sample, these dependencies
have the stepped character. At low temperatures,
there is a divergence ZFC and FC curves, the
value of which depends on the magnetic field.
Herewith the larger field leads to the smaller
magnitude of the divergence. At the field of 30
mT, the magnetization increases monotonically
in the temperature range from 3 to 240 K, when
in the range from 240 to 270 K the
magnetization «jumps». After that, in the range
of 270–350 K the magnetization continues to
increase, but with the higher rate. At the field
value of 120 mT and 200 mT ZFC curves
increase monotonically in the all range of
temperature. Enlarging the value of the
magnetic field leads to moving of the point of
intersection of the ZFC and FC curves to lower
temperatures. Unlike the sample based on
nickel, which has been described above, in this
case the dependence have not a jump in
magnetization at the temperature range 30–55
K.
CONCLUSION
In general, current investigations have shown
the influence of the presence of nanostructured
material (IOLS), the type of material and the
thickness of structure on the total magnetization
behavior depending on the temperature. Nature
82
of the detected feature is not absolutely clear at
the moment, but it seems, that further analysis
of the data and additional research will help to
resolve this problem.
REFERENCES
[1]
A. A. Mistonov, N. A. Grigoryeva, et al.,
Phys. Rev. B 87, 220408 (2013).
[2]
K. S. Napolskii, A. Sinitskii, et al.,
Physica B 397, 23 (2007).
[3]
S. V. Grigoriev, K. S. Napolskii, N. A.
Grigoryeva, et al, Phys. Rev. B 79, 045123
(2009)
83
Transverse coherence measurements at P04 beamline
at PETRA III
A.Singer1, P.Skopintsev1,5, J.Bach2, L.Müller1, B.Beyersdorf2,
S.Schleitzer1, O.Gorobtsov1, A.Shabalin1, R.Kurta1, D.Dzhigaev1,6,
O.M.Yefanov1, L.Glaser1, A.Sakdinawat3, Y.Liu4, D.Attwood4,
G.Grübel1, R.Fromter2, H.P.Oepen2, J.Viefhaus1,
I.A.Vartanyants1,6
1
Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany,
Universität Hamburg, Institut für Angewandte Physik, 20355 Hamburg, Germany,
3
SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA,
4
University of California, Berkeley, CA 94720, USA,
5
NRC “KurchatovInstitute”, 123182 Moscow, Russia,
6
National Research Nuclear University, “MEPhI”, 115409 Moscow, Russia
[email protected]
2
INTRODUCTION
The experiment for measuring transverse
coherence of soft x-ray beam was conducted on
P04 Variable Polarization XUV Beamline
Station of PETRA III Synchrotron Radiation
Source at DESY in Hamburg during
commissioning. The undulator period length
was adjusted to have resonant energy at 400 eV
and the monochromator exit slits separation was
varied. We measured vertical transverse
coherence of the synchrotron beam with double
pinholes apertures, like in classical Young’s
experiment. We then have demonstrated that
transverse coherence of the beam can be
successfully measured with an advanced method
utilizing non-redundant arrays (NRA) of slits.
THEORY
Transverse coherence. An important measure
directly related to interference phenomena and
describing correlation between two complex
values of the electric field E1, E2 at two points in
space is complex degree of coherence (CDC).
By definition, it is expressed by [1]:
where
is the ensemble average and * denotes
the complex conjugate. This parameter is a
normalized version of the mutual coherence
function (MCF) or correlation function of the
light field. In the presence of low effects of
temporal coherence, i.e.
, CDC becomes
or simply
and is thereby called the
degree of transverse coherence.
Multiple slits diffraction. It can be shown [2]
that Fourier transform
of the interference
pattern observed in N slits diffraction
experiment is:
,
where is beam intensity at slit ,
— slits
and
separation,
— Dirac delta
function
is Fourier transform of the intensity
distribution for single slit diffraction,
—
84
relative phase,
denotes convolution and |
is transverse coherence.
|
If all the distances between the slits are unique,
then peaks would be observed in the reciprocal
space of the diffraction pattern intensity. If
heights (i.e. maxima of
|) of the peaks
and
and intensities at the slits
are known, then a following system of equations
might be solved and
found for all
slits
Figure 2. Fourier transform of the diffraction
pattern. The slits used in the experiment are
shown in the upper-right corner of the figure in
a box.
RESULTS
The undulator period length was tuned to have
resonant energy at 400 eV. The monochromator
slits were separated by 50 or 200 µm. Five and
six slits NRA and double pinholes diffraction
patterns were collected with a CCD camera and
then Fourier transformed (see Fig.1 and 2).
Then the degree of vertical transverse coherence
was retrieved. In case of diffraction from two
apertures the transverse coherence was found on
a single distance, whereas in case of multiple
apertures (e.g. 5 slits) the transverse coherence
was found on several distances (e.g. at ten
distances). It was found that exit slits opening
reduces the coherence length. For 400 eV beam
and slits separation of 50 µm, the coherence
length was 8.9 µm (beam FWHM was 20 µm),
whereas for slits separation of 200 µm the
coherence length was 4.5 µm (beam FWHM 38
µm). The results for beam diffraction on NRA's
of slits were identical to those found with
double pinholes aperture (see Fig. 3).
Figure 1. Typical diffraction image of nonredundant set of five slits at 400 eV and exit
slits separation of 50 µm.
Figure 3. Spatial coherence found for 400 eV
beam and slits separation of 200 µm measured
with double pinholes (gray curve) and five slits
NRA (red curve). Beam FWHM is 38 µm.
CONCLUSIONS
The non-redundant array of slits offer a very
useful and rapid method for determination of
85
synchrotron beam coherence properties. The
technique allows one to measure transverse
coherence at several distances at a single
exposure. The NRA approach holds correct for
undulator radiation and gives the same results as
in classical Young’s double pinholes
experiment. The NRA method could hold
extremely useful for unstable radiation sources
such as free-electron lasers.
REFERENCES
1. J.W. Goodman, Statistical optics (Wiley,
New York, 1985).
2. Y. Mejia and A. I. Gonzalez, Opt. Commun.
(2007), 273, 428
86
Spatially resolved orientational order in binary colloid films
studied by nano-beam X-ray cross correlation analysis
Martin A. Schroer1, Christian Gutt1, Felix Lehmkühler1, Birgit
Fischer1, Ingo Steinke1, Alessandro Ricci1, Fabian Westermeier1,
Sebastian Kalbfleisch2, Michael Sprung1, Gerhard Grübel1
1
2
Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
Georg-August-Universität Göttingen, Friederich-Hund-Platz 1,37077 Göttingen, Germany
[email protected]
ABSTRACT
Scattering techniques are powerful methods for
studying soft matter systems. As these samples
often lack long range order usual approaches to
analyze the two-dimensional scattering patterns
only focus on the radially averaged signal.
However, often there is a subtle variation of this
azimuthal intensity that is lost by the averaging
process. Accessing this information allows it to
learn more about the underlying orientational
order within the sample. Especially, the local
heterogeneity of the structure can be explored.
This type of information can be determined by
the X-ray cross correlation analysis (XCCA)
technique [1].
This XCCA approach was used to investigate
the local structures of thin films made out of
dried binary mixtures of colloids. These films
are special types of colloidal crystals. The
interest in these structures has increased recently
as they can exhibit exciting new properties. For
instance, three-dimensional colloidal crystals
made out of uniformly-sized colloids can be
used as photonic crystals [2]. Their functional
properties are related to the underlying crystal
structure. Variation of the building-blocks of
these artificial crystals allows to tune the
characteristic responses to external fields and
thus to fabricate tailored materials. Special
examples are crystals made out of two types of
colloids with different sizes. Such binary
colloidal mixtures of particles are known to
show a richer phase diagram of crystal
structures than single component systems [3]. A
detailed knowledge of the local structures of
these ‘colloidal alloys’ is mandatory for the
fabrication of materials with dedicated
functional properties.
In order to investigate the local structure of
colloidal films, nano-beam X-ray scattering
measurements on dried binary colloidal films of
different mixing ratios were performed. The soobtained two-dimensional small angle X-ray
scattering (SAXS) patterns were analyzed with
the XCCA technique. This approach allows us
to study the local orientational correlations
within the colloidal films made out of particles
with radius of 11 nm and 19 nm. Due to the
nanometer size of the X-ray beam (< 400 x 400
nm2), the orientational correlations of the
colloidal films can be spatially resolved. Thus,
real space maps of the electron density [4] based
on the total scattering intensity, and of local
correlations and orientations within the
nanoparticle films (based on XCCA) can be
obtained.
Using such spatial maps the average correlation
length within a sample can be measured [5].
This was performed for both the intensity and
the cross correlation maps and allows to
determine the average extent of correlated
regions.
In summary, by studying these maps with this
’orientation weighted’ contrast the local
structure of the mixtures can be extracted. This
information is completely inaccessible by the
usual scattering approaches.
87
REFERENCES
[1] P. Wochner, C. Gutt, T. Autenrieth, T. Demmer,
V. Bugaev, A. Diaz Ortiz, A. Duri, F. Zontone, G.
Grübel, and H. Dosch, Proc. Natl. Acad. Sci. USA
106, 1151 (2009).
[2] A. Blanco et al., Nature 405, 437 (2000).
[3] M.H. Kim,S. Hyuk, and O.O. Park, Adv. Mater
[4] M. Fratini, N. Poccia, A.Ricci, G. Campi,
M. Burghammer, G. Aeppli, A. Bianconi, Nature
466, 841 (2010)
[5] A.C.Y. Liu, M.J. Neish, G. Stokol, G.A.
Buckley, L.A. Smillie, M.D. de Jonge, R.T. Ott, M.J.
Kramer, and B.J. Bourgeois, Phys. Rev. Lett. 110,
205505 (2013)
17, 2501 (2005).
88
Adiabatically Focusing Lenses
M. Scholz1, J. Patommel1, S. Hönig1, S. Ritter1, A. Jahn2,
C. Richter2, J. W. Bartha2,U. Bösenberg3, G. Falkenberg3
and C. G. Schroer1
1
2
Institute of Structural Physics, TU Dresden, D-01062 Dresden, Germany
Institute for Semiconductors and Microsystems, TU Dresden, D-01062 Dresden, Germany
3
Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg, Germany
Focusing optics for hard x rays lack of
relatively small numerical apertures. In fact,
the numerical aperture of all x-ray optics
applied so far is limited by the critical angle
of total reflection, i. e., their numerical
aperture is lower than the square root of
twice the refractive decrement. There was
the discussion in the x-ray optics community
whether this is a fundamental physical limit
for any focusing x-ray optic [1].
In [2] the design of a so-called Adiabatically
Focusing Lens (AFL) was proposed, a new
kind of x-ray lens with a numerical aperture
that, at least in theory, exceeds the size of
the critical angle of total reflection. The AFL
is composed of many single refractive lenses
with apertures that are gradually adapted to
the size of the converging x-ray beam,
allowing to increase the refractive power per
length without compromizing the incident
aperture of the whole lens. The fabrication
of such an AFL is quite challenging, since
the size of the single lenses becomes very
small. For this reason, no AFL had been
realized for quite a long time.
During a cooperation with the Institute for
Semiconductors and Microsystems, TU
Dresden, we finally succeeded in
manufacturing
Adiabatically
Focusing
Lenses made of silicon. We performed an
experiment at the nanoprobe endstation of
the beamline P06 at PETRA III, where we
combined an AFL with a Nanofocusing Lens
(NFL) and investigated the beam profile by
scanning coherent x-ray diffraction imaging
(ptychography). We demonstrated a focus
size of 17.1 nm in the vertical direction
(generated by the AFL) by 53.4 nm in the
horizontal direction (generated by the NFL)
at a photon energy of 20 keV. This alone is
an outstanding result, as this was is one of
the smallest foci that has ever been achieved
for hard x rays. Beyond that, the vertical
numerical aperture of 1.64 mrad exceeds the
critical angle of total reflection of 1.56 mrad
for silicon at the used x-ray energy.
REFERENCES
[1] C. Bergemann, H. Keymeulen, and J. F.
van der Veen, Phys. Rev. Lett. 91, 204801
(2001).
[2] C. G. Schroer and B. Lengeler, Phys.
Rev. Lett. 94, 054802 (2005).
* [email protected]
Figure 1: Caustic and beam profile of the focus generated by the AFL/NFL.
89
Field induced chirality in helix structure of
magnet/nonmagnet multilayers
V. Tarnavich1, D. Lott2, S. Mattauch3, V. Kapaklis4, S. Grigoriev1,5
1
Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia, [email protected]
2
Helmholtz Zentrum Geesthacht, 21502 Geesthacht, Germany
3
Jülich Centre for Neutron Science (JCNS), 85747 Garching, Germany
4
Uppsala University, Uppsala, Sweden
5
Saint-Petersburg State University, Ulyanovskaya 1, 198504 Saint-Petersburg, Russia
Corresponding Author’s Email: [email protected]
The rare-earth magnetism attracted much
attention in the light of the discovery of 3D long
range order, which can occur in rare
earth/yttrium superlattice (SL) structures [1,2,3].
A few years ago we have demonstrated that
Dy/Y magnetic multilayer structures (MMLs)
possess a coherent spin helix with a preferable
chirality induced by the magnetic field [1]. A
magnetic field applied in the plane of the sample
upon cooling below TN is able to repopulate the
otherwise equal population numbers for the leftand right-handed helixes. The experimental
results strongly indicate that the chirality is
caused
by
Dzyaloshinskii-Moriya (DM)
interaction due to the lack of the symmetry
inversion on the interfaces.
The polarized neutron reflectometry is used to
show that metal magnetic/nonmagnetic (Ho/Y)
multilayer structures posses a coherent spin
helix propagating through many Ho/Y bilayers.
The samples of different thicknesses of Ho and
Y layers were grown by molecular-beam(S1),
epitaxy
techniques:
[Ho45Å/Y30Å]
[Ho25Å/Y20Å]
(S2),
[Ho20Å/Y30Å]
(S3),
[Ho60Å/Y30Å] (S4), [Ho25Å/Y40Å] (S5).
We
measured the chirality parameter γ=(I+- I-)/(I+ +
I-) of the multilayers as a function of the
temperature and magnetic field. This parameter
is directly related to the imbalance between the
left- and right-handed spiral, where I+/- is the
integrated intensity of the helical peak with up
(+) and down (-) neutrons. The chirality γ is
equal to 0 for all samples cooled in zero field.
The magnetic field of 1 T, applied in the plane
of the sample upon cooling below TN, induces
non-zero chirality, which almost independent on
the temperature for the samples S1, S2, S3.
Opposite to it the field does not induce any
chirality for samples S4 and S5.
We assume the net chirality in Ho/Y
systems appears due to symmetry breaking on
magnetic-non-magnetic interface. We expect
that the interfacial defects, emerging due to the
overlap between magnetic Ho and nonmagnetic
Y atoms, can produce a DM interaction normal
to the interface in magnetic heterostructures
what leads to the predominant chirality, based
on the theoretical work of Haraldsen and
Fishman [4].
REFERENCES
[1] Ross W. Erwin, J. J. Rhyne, M. B. Salamon,
J. Borchers, S. Sinha, R. Du, J. E. Cunningham,
C. P. Flynn, Phys. Rev. B 35, 6808 (1987).
[2] R. A. Cowley, D. F. McMorrow, A.
Simpson, D. Jehan, P. Swaddling et al., J. Appl.
Phys., Vol. 76, p. 6274-6377 (1994).
[3] C. de la Fuente, R. A. Cowley, J. P. Go_; R.
C. C. Ward, M. R.Wells, D. F. McMorrow, J.
Phys. Condens. Matter, Vol. 11, p. 6529-6541
(1999).
[4] J. T. Haraldsen and R. S. Fishman, Phys.
Rev. B 81, 020404(R) (2010).
90
Structural Investigation of Glasses with Magnetic
Nanoprecipitates
N.N. Trofimova, 1I.S. Edelman,2 O.S. Ivanova,2 R.D. Ivantsov,2
E.A. Petrakovskaja,2 D.A. Velikanov,2 V.N. Zabluda,2
and Y.V. Zubavichus2
National Research Center “Kurchatov Institute”, Moscow, Russia
L.V. Kirensky Institute of Physics SB RAS, Krasnoyarsk, Russia
[email protected]
INTRODUCTION
Magnetic properties together with optical
transparency are remarkable features of oxide
glass
materials
containing
magnetic
nanoparticles. The nanoparticles are formed
during a specific heat treatment and their
structure is strongly dependent on initial glass
composition and thermal regime. On the other
hand, it is the structure of magnetic particles
that determines the functional properties of a
glass sample. The previous study [1] has
revealed that the difference in the magnetic
properties of glasses is due to the local order
around Fe atoms and size of maghemite (γFe2O3) nanocrystallites. With increasing
treatment temperature a distinct long-range
order in environment of Fe atoms emerges,
whereas the local structure around other dopant
atoms (e.g., rare-earth) remains virtually
unchanged. Thus, a clear correlation between
the local structure of iron atoms and magnetic
properties is established.
APPROACH
The samples under investigation are similar to
those previously analyzed. The glass matrix
contain Al2O3, GeO2, K2O and B2O3 doped with
various additives, including iron, bismuth,
yttrium, and rare-earth elements. The XRD data
were collected in the Kurchatov Synchroton
Radiation Centre in the transmission geometry
using Imaging Plate detector, wavelength of
radiation was 0.68886 Å, exposure time was
about 20 minutes. Also room temperature EMR
spectra were recorded.
According to the EMR spectra, all samples can
be formally divided into three groups (Fig.1)
whereas XRD reveals that the glasses can be
classified into four groups with different
composition of nanocrystalline phase (Fig.2).
These groups are A (only maghemite); B1
(maghemite and K2Al2B2O7); B2 (maghemite,
YBO3 and δ-Bi2O3); B3 (maghemite and,
presumably, PbO).
2000
3
1500
Intensity, a.u.
2
1000
2
500
1
0
0
100
200
300
400
500
600
Fig.1
- Three types of room temperature EMR spectra.
B, mT
300
250
Intensity, a.u.
1
200
150
100
B3
B2
50
B1
A
10
20
30
2θ,°
40
Fig.2
–Four types of diffraction patterns.
We observe no clear dependence between the
crystallite size, lattice parameter and
temperature of treatment. We assume that this is
91
due to the varied composition of the glasses
obtained at different temperature and complex
effect of additives on the structure formation of
maghemite nanoprecipitates. Nonetheless, some
common trends in the shape of EPR signal and
size of crystallite is observed (Fig.3).
CONCLUSIONS
XRD data confirm the earlier suggested
influence of the crystallite size of maghemite
nanoprecipitates on the magnetic properties of
the glass samples. Simultaneous modification of
glass composition and treatment temperature
complicates the analysis to reveal clear
correlations. A further study using multi-edge
XAFS (EXAFS and XANES) spectroscopy is
planned to clarify the «structure-property»
relationships.
REFERENCES
[1] I. Edelman, O. Ivanova, R. Ivantsov, D.
Velikanov, V. Zabluda, Y. Zubavichus, A.
Veligzhanin,V. Zaikovskiy, S. Stepanov, A.
Artemenko, J. Curély and J. Kliava, J. Appl.
Phys. 2012, V.112, 084331.
Fig.3 — Correlation between the crystallite size
of maghemite phase in group A (top graph) and
groups B1, B2, B3 (bottom graph) with the
shape of the EMR signal. The value of 2.5 on
the abscissa used for samples that have a
transitional (between group 2 and group 3)
shape of the EMR signal.
92
Fluorescence Properties of CdSe/CdS Nanorods on Gold
Nanoparticles
Wiebke Friedrich1, Kathrin Hoppe1, and Horst Weller1
1
Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany
[email protected]
INTRODUCTION
Nanoparticles exhibit fascinating optical
properties that can be used in various
applications. The increasing understanding of
these properties opens the door for advanced
nanomaterial design.1
Among other areas, the research field on optical
properties of gold and semiconductor
nanocrystals on the single particle level, such as
blinking, quenching and surface plasmon
resonances, has grown in the last decades.2,3,4
Although knowledge in this respect has
extended greatly, the processes of radiative and
non-radiative
decay
in
fluorescing
semiconductor nanorods (SNR) on a single
particle level still represent a topic with
tremendous scientific potential.
The investigation of distance dependent
electromagnetic
field
enhancement
and
quenching sets the basis for further application
in photovoltaic technologies.
In this work the distance dependent fluorescence
intensity of CdSe/CdS nanorods on a gold
nanoparticle (GNP) film is studied. The distance
dependence
of
electromagnetic
field
enhancement by surface plasmon resonances
(SPR) of the GNP and quenching by Förster
resonance energy transfer (FRET) is
determined.
FRET describes the mechanism of non-radiative
energy transfer between an excited donor and an
acceptor in the ground state.5 When looking at
metal nanoparticles another effect, the
enhancement of the electromagnetic field due to
SPR, has to be considered.2,3,4
APPROACH
Gold nanoparticle films are prepared by a layerby-layer spin-coating technique on a glass
substrate.6 The highly luminescent SNR are
synthesized by a seeded-growth based hotinjection method.7
A diluted solution of SNR is spin-coated on a
glass substrate half covered with a GNP film.
The fluorescence intensity of the single SNR is
determined using a confocal laser scanning
microscope with a single photon counting unit
and a spectrometer. Via a polymer film between
SPR and GNP film the distance can be adjusted.
The polymer film thickness is measured by
atomic force microscopy (AFM).
In order to study the anisotropic fluorescing
properties and geometrical effects on
photoluminescence of the SNR it is necessary to
determine the energy transfer between an
ordered gold nanorod (GNR) assembly –in
contrast to GNP films —
and the
semiconductor nanocrystals.
Hence, highly monodisperse GNR are
synthesized by a wet-chemical seeded-growth
approach.8 Standing assemblies of the GNR are
manufactured by a drop-casting technique.9
These arrays represent the substrate for the
ongoing measurements on the fluorescence
enhancement and quenching of single SNR.
Depending on the polymer film thickness the
fluorescence intensity of the SNR on GNP films
is either enhanced or quenched in
comparison to the intensity on glass
.
The fluorescence intensity is given by:
with the radiative emission rate
non-radiative energy transfer rate
93
.2,3
and the
Due to the plasmon resonances, the fluorescence
intensity of the SNR on GNP depends on the
2,3
electromagnetic enhancement factor
:
The normalized intensity
given by2,3
is for this system is
This correlation leads to the following results of
the fluorescence intensity:
Figure 3 graph of the distance dependence of
the blinking corrected normalized intensity .
Since the SNR show on and off states, the
normalized intensity had to be corrected by the
respective blinking behavior on GNP films and
glass.
As shown in Figure 1, the normalized intensity
increases with increasing film thickness. The
fluorescence intensity of the SNR on the GNP
film exceeds the fluorescence on glass in the
measurements with a GNP-SNR distance of
roughly above 50 nm. This observation is in
accordance to the suggested process of the
fluorescence enhancement due to plasmon
resonances, although measurements have to be
extended to determine the maximum critical
distance for the effect. At small SNR-GNP
distances the fluorescence is quenched, which
confirms the concept of FRET.
CONCLUSIONS AND OUTLOOK
A distance dependent quenching and
fluorescence enhancement of single SNR on a
GNP film was measured. The results are
consistent with theoretical concepts.3,4,10
Measurements of the determined effect have to
be further evaluated.
Currently, the distance dependent quenching
and fluorescence enhancement of CdSe/CdS
nanorods on ordered GNR assemblies is
investigated. Thus, polarization effects or even
an angular dependence of the optical properties
can be determined using the concept of Chance,
Prock and Silbey and the presented setup.11
REFERENCES
(1) Guerrero-Martínez, A.; Grzelczak, M.; LizMarzán, L. ACS Nano 2012, 6, 3655-3662.
(2) Govorov, A.O.; Bryant, G.W.; Zhang, W.;
Skeini, J.L.; Kotov, N.A.; Slocik, J.M.; Naik,
R.R. Nano Lett. 2006, 6, 984-994.
(3) Ito, Y.; Matsuda, K.; Kanemitsu, Y. Phys.
Rev. B 2007, 75, 033309-033313.
(4) Fu, Y; Lakowicz, J.R. Laser & Photon. Rev.
2009, 3, 221-232.
(5) Forster, T Discuss. Faraday Soc. 1959, 27,
7-17.
(6) Schlicke, H.; Schröder, J.H.; Trebbin, M.;
Petrov, A.; Ijeh, M.; Weller, H. Vossmeyer, T.
Nanotechnology 2011, 22, 305303-305312.
(7) Carbone, L.; Nobile, C.; De Giorgi, M.;
Della Sala, F.; Morello, G.; Pompa, P.; Hytch,
M.; Snoeck, E.; Fiore, A.; Franchini, I.R.;
Nadasan, M.; Silvestre, A.F.; Chiodo, L.;
Kudera, S.; Cingolani, R.; Krahne, R.; Manna,
L. Nano Lett. 2007, 7, 2942-2950.
(8) Ye, X.; Zheng, C.; Chen, J.; Gao, Y.;
Murray, C.B. Nano Lett. 2013, 13, 765-771.
(9) Sreeprasad, T.S.; Samal, A.K.; Pradeep, T.
Langmuir 2008, 24, 4589-4599.
(10) Jander, S.; Kornowski, A.; Weller, H. Nano
Lett. 2011, 11, 5179-5183.
(11) Chance, R.R.; Prock, A.; Silbey, R. J,
Chem. Phys. 1976, 65, 2527-2531.
94
................................................................................................................................- 5 RACIRI SUMMER SCHOOL-PROGRAM.......................................................................................................................- 5 TWO ASPECTS OF MY RESEARCH IN THE FIELD OF SCATTERING ................................................................... 10
ADLMANN FRANZ1 ................................................................................................................................................................ 10
MAGNETIC STRUCTURE OF MNGE IN A WIDE TEMPERATURE RANGE........................................................... 11
E. V. ALTYNBAYEV1,2, S.-A. SIEGFRIED3, N.M. POTAPOVA1, V. A. DYADKIN1,4, E. V. MOSKVIN1,2, D. MENZEL5, CH.
DEWHURST6, R.A. SADYKOV7,8, L.N. FOMICHEVA8, A.V. TSVYASHCHENKO8, S. V. GRIGORIEV1,2 ....................................... 11
STRUCTURE OF THE VANADIUM — DOPED ND5MO3OY SINGLE CRYSTAL.................................................... 13
A.M. ANTIPIN1, O.A. ALEKSEEVA1, N.I. SOROKINA1, E.P. KHARITONOVA2, V.I. VORONKOVA2 .......................................... 13
APPLICATION OF THE METHOD OF NEUTRON ACTIVATION ANALYSIS FOR DETERMINATION OF
NANOPARTICLES TRANSPORT PROPERTIES IN BIOLOGICAL TISSUES IN VIVO .......................................... 14
А.А. ANTSIFEROVA¹.............................................................................................................................................................. 14
INDUSTRIAL APPLICATIONS OF SYNCHROTRON RADIATION............................................................................ 16
G.A. APPLEBY ....................................................................................................................................................................... 16
DEVELOPMENT OF THE METHOD FOR TIME RESOLVING OBSERVATION OF ROCKING CURVES BY
ULTRASONIC MODULATION OF THE LATTICE PARAMETER.............................................................................. 17
A.E. BLAGOV1, A.V. TARGONSKY1, P.A. PROSEKOV1, YU. V. PISAREVSKY1, M.V. KOVALCHUK 1,2 ................................... 17
TRANSPORT PROPERTIES OF THE LA0.75CA0.25MNO3 MANGANITE ................................................................ 18
I.A. BONDAREV1 AND N.V. VOLKOV1,2 ................................................................................................................................. 18
DIELECTRIC GLASS-CERAMICS FOR MOBILE APPLICATIONS IN THE GHZ FREQUENCY RANGE......... 19
HUBERTUS BRAUN1,2,3, MARTIN LETZ1, HANS-JOACHIM ELMERS2,3, MARTUN HOVHANNISYAN1,4 ....................................... 19
POROSITY CHARACTERIZATION OF UHMWPE-DERIVED MATERIALS FOR MEDICAL APPLICATION . 20
IU.BYKOVA 1, V.ALTAPOVA 1,3, S.LEBEDEV 1, T.BAUMBACH 2,3, I.KHLUSOV 1,4 AND V.F. PICHUGIN 1 .................................. 20
STRUCTURE AND SELF-ORGANIZATIONIN MAGNETIC LIQUIDS ....................................................................... 23
HAUKE CARSTENSEN, MAX WOLFF, VASSILIOS KAPAKLIS................................................................................................... 23
COMPARATIVE MORPHOLOGY OF MACROMOLECULES OF IMMUNOGLOBULIN-M AND HUMAN
RHEUMATOID FACTOR FROM SAXS DATA ................................................................................................................ 24
DENIZA I. CHEKRYGINA1, VLADIMIR V. VOLKOV1, VICTOR A. LAPUK2, ELENA YU. VARLAMOVA3 .................................... 24
SURFACE MODIFICATION OF METAL OXIDE NANOPARTICLES THROUGH CONTROLLED RADICAL
POLYMERIZATION FOR IMPROVING ELECTRICAL INSULATION IN HVDC CABLES .................................. 27
CARMEN COBO SÁNCHEZ, MARTIN WÅHLANDER, LINDA FOGELSTRÖM, ANNA CARLMARK, ULF GEDDE, EVA
MALMSTRÖM1 ....................................................................................................................................................................... 27
SAXS DERIVED 3D-MODEL OF THE NOVEL BACTERIAL FRUCTOSE 1,6-BISPHOSPHATE ALDOLASE.... 28
L.A. DADINOVA1, E.V. RODINA2, N.N. VOROBIEBA2, E.V. SHTYKOVA1 ............................................................................... 28
95
STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF AMORPHOUS SILICON MODIFIED BY
FEMTOSECOND LASER RADIATION ............................................................................................................................. 30
A.V. EMELYANOV1,2, P.A. FORSH1,2, P.K., A.G. KAZANSKII2, M.V. KHENKIN2, KASHKAROV1,2, P.G. KAZANSKY3 .............. 30
STRUCTURE OF LUMINESCENT GLUCONACETOBACTER XYLINUS CELLULOSE NANOCOMPOSITES
INVESTIGATED BY SMALL ANGLE SCATTERING .................................................................................................... 33
EZDAKOVA K1, KOPITSA G.1, SMYSLOV R.2, BUGROV A.2, NEKRASOVA T.2, KHRIPUNOV A.2 , ANGELOV B.3 PIPICH V.4,
SZEKELY N.4 ......................................................................................................................................................................... 33
ORIENTATIONAL ORDERING AND PACKING EFFECTS OF SPINDLE SHAPED PARTICLES
INVESTIGATED BY SPATIALLY RESOLVED COHERENT SAXS ............................................................................ 35
B. FISCHER 1,2, C.GUTT 1,2, J. WAGNER 3, F. LEHMKÜHLER 1,2, C. PASSOW 3, M. SPRUNG 1,G. GRÜBEL12, .............................. 35
HIGHLY ORDERED MOLECULAR MATERIALS STUDIED BY SYNCHROTRON TECHNIQUES .................... 37
STEFAN FISCHER, JOSEF HIRTE, BERT NICKEL1 ..................................................................................................................... 37
SPECTROMETER FOR HARD XFEL BASED ON DIFFRACTION FOCUSING........................................................ 38
O. Y. GOROBTSOV1,2, V. G. KOHN1 AND I. A. VARTANYANTS2,3 ........................................................................................... 38
EXAFS AND XRD STUDIES OF TI50NI25CU25 SHAPE MEMORY ALLOY AT THE MARTENSITIC
TRANSFORMATION ............................................................................................................................................................ 39
ALEXEY MENUSHENKOV1, OLGA GRISHINA1, ALEXANDER SHELYAKOV, ALEXANDER YAROSLAVTSEV, NIKOLAY
SITNIKOV1, YAN ZUBAVICHUS2, ALEXEY VELIGZHANIN2, JOSEPH BEDNARCIK3, ROMAN CHERNIKOV3................................ 39
COMBINED ELECTRICAL AND GRAZING INCIDENCE X-RAY MEASUREMENTS OF POLY(3HEXYLTHIOPHENE) THIN FILM FORMATION........................................................................................................... 41
LINDA GRODD1, ULLRICH PIETSCH1, SOUREN GRIGORIAN1 ................................................................................................... 41
THERMOTROPIC PHASE TRANSITIONS IN MODEL LIPID MEMBRANES BASED ON CERAMIDE 6: PH
INFLUENCE ........................................................................................................................................................................... 43
A.YU. GRUZINOV1, M.A.KISELEV2, E.V. ERMAKOVA2, A.V. ZABELIN1 ................................................................................ 43
HARD X-RAY NANOPROBE AT BEAMLINE P06 AT PETRA III................................................................................ 44
R.HOPPE1, A. GOLDSCHMIDT1, F. SEIBOTH1, P. BOYE1, J.M. FELDKAMP1, J. PATOMMEL1, D. SAMBERG1, A. SCHROPP1, S.
RITTER1, V. MEIER1, S. HÖNIG1, C. BAUMBACH1, A. SCHWAB1, S. STEPHAN1, G. FALKENBERG2, G. WELLENREUTHER2, N.
REIMERS2, P. BHARGAVA2, T. CLAUßEN2, J. REINHARDT2 AND C.G. SCHROER1,.................................................................... 44
FABRICATION AND QUALITY CONTROL OF THE X-RAY DIFFRACTION GRATINGS AT ANKA ................ 45
D. KARPOV1, V. WEINHARDT1,2, D. KUNKA3, F. CHEN1, T. BAUMBACH1............................................................................... 45
STUDY OF SILICON-ON-SAPPHIRE STRUCTURAL QUALITY BY X-RAY DIFFRACTOMETRY,
REFLECTIVITY AND TEM METHODS............................................................................................................................ 48
BLAGOV A.E.1, VASILIEV A.L.1, KONDRATEV O.A.1, PISAREVSKIY YU.V.1, PROSEKOV P.A.1, SEREGIN A.YU.1 ................. 48
MONTE-CARLO SIMULATIONS OF THERMAL NEUTRON FILTER AND NEUTRON GUIDE SYSTEM FOR
REVERANS REFLECTOMETER ....................................................................................................................................... 50
P. KONIK1, E. MOSKVIN1,2 ..................................................................................................................................................... 50
INFLUENCE OF RADIATION DOSE ON THE STRUCTURE OF CYTOCHROME C NITRITEREDUCTASE.... 51
LAZARENKO VLADIMIR1, POLYAKOV KONSTANTIN2 ............................................................................................................. 51
PHASE DYNAMICS OF JOSEPHSON JUNCTIONS........................................................................................................ 53
S. YU. MEDVEDEVA1,2 AND YU. M. SHUKRINOV 1 ................................................................................................................. 53
THREE-DIMENSIONAL ARTIFICIAL SPIN ICE IN NANOSTRUCTURED CO ON AN INVERSE OPAL-LIKE
LATTICE................................................................................................................................................................................. 55
96
A.A. MISTONOV1, N.A. GRIGORYEVA1, H. ECKERLEBE2, N.A. SAPOLETOVA3, K.S. NAPOLSKII3, A.A. ELISEEV3,
D. MENZEL4, S.V. GRIGORIEV1,5 ........................................................................................................................................... 55
APPLYING THE SYNCHROTRON RADIATION FOR THE STUDYING PHASE-FORMATION DURING
COMBUSTION OF THE ALUMINUM NANOPOWDER IN AIR................................................................................... 57
ANDREY V. MOSTOVSHCHIKOV, ALEXANDER P. ILYIN, NIKOLAY A. TIMCHENKO ............................................................... 57
STRUCTURE OF SUPPORTED CATALYSTS: X-RAY SYNCHROTRON DIAGNOSTICS IN SITU ...................... 60
MURZIN V.Y.1, 2, ZUBAVICHUS Y.V.1, VELIGZHANIN A.A.1, BRUK L.G.3, BUKHTIYAROV V.I.4 ............................................ 60
PRESSURE-INDUCED PHASE TRANSITIONS IN THE LANGASITE STRUCTURE COMPOUND
BA3TAFE3SI2O14.................................................................................................................................................................. 63
P. G. NAUMOV1,2, I. S. LYUBUTIN1, V. KSENOFONTOV2, S. MEDVEDYEV3 AND C. FELSER3................................................... 63
GRAFTED POLYLACTIDE PARTICLES AND THEIR REPULSIVE FORCES ......................................................... 66
ROBERTUS WAHYU N. NUGROHO, TORBJÖRN PETTERSSON, KARIN ODELIUS, ANDERS HÖGLUND, AND ANN-CHRISTINE
ALBERTSSON ......................................................................................................................................................................... 66
THE REACTION OF DECOMPOSITION OF MNB2H8 ................................................................................................... 67
PANKIN ILYA1, GUDA ALEXANDER 1, FILINCHUK YAROSLAV 2, SOLDATOV ALEXANDER 1 ................................................... 67
MÖSSBAUER STUDY OF THE FESETE COMPOUND SYSTEM................................................................................. 69
PERUNOV I.V. 1, FROLOV K.V.1, VASYUKOV D.M.1,LYUBUTIN I.S.1, KOROTKOV N.YU.1, BELIKOV V.V.2, KASAKOV S.M.2,
ANTIPOV E.V.2 ...................................................................................................................................................................... 69
STUDY OF NANOSTRUCTURAL ORGANIZATION OF ANIMAL HAIR BIOLOGICAL FIBER WITH X-RAY
DIFFRACTION METHODS USING SYNCHROTRON RADIATION ........................................................................... 70
A.YU. GRUZINOV1, A.A. VASILYEVA2 G.S. PETERS1, V.V. STEPANOVA2 I.A. STAROSELSKIY1,3 A.V. ZABELIN1,2, A.G.
MALYGIN4 A.A. VAZINA1,2 .................................................................................................................................................... 70
PREFOCUSSING AT PETRA II BEAMLINE P06............................................................................................................. 72
S. RITTER1, S. HÖNIG1, C. BAUMBACH1, J. PATOMMEL1, M. KAHNT1, D. SAMBERG1, R. HOPPE1, F. SEIBOTH1, J. REINHARDT2,
U. BÖSENBERG2, N. REIMERS2, G. WELLENREUTHER2, G. FALKENBERG2 AND C. G. SCHROER1 ........................................... 72
HIGH-RESOLUTION CHEMICAL IMAGING OF GOLD NANOPARTICLES USING HARD X-RAY
PTYCHOGRAPHY ................................................................................................................................................................ 73
JULIANE REINHARDT(1*,2), ROBERT HOPPE(2), GEORG HOFMANN(3), CHRISTIAN D. DAMSGAARD(4), DIRK SAMBERG(2), JENS
PATOMMEL(2), GERALD FALKENBERG(1), GERD WELLENREUTHER(1), PREETY BHARGAVA(1), JAN-DIERK GRUNWALDT(3) AND
CHRISTIAN G. SCHROER(2) ..................................................................................................................................................... 73
APPLICATION OF XAFS FOR STUDY CU, ZN IN SOIL ............................................................................................... 75
PODKOVYRINA YU.S. 1, SOLDATOV A.V.1, NEVIDOMSKAYA D.G.2, MINKINA T.M.3 ............................................................ 75
PHASE SEPARATION OF COMPLEX HALF-DOPED 154SM0.32PR0.18SR0.5MNO3 MANGANITE............................. 77
G. SARAPIN1,2, A. KURBAKOV1,2, V. RYZHOV2, C. MARTIN3, A. MAIGNAN3 ......................................................................... 77
DEVELOPMENT AND CHARACTERIZATION OF A NEW MAGNETIC SAMPLE ENVIRONMENT FOR
EXPERIMENTS AT P10 BEAMLINE OF PETRA III FACILITY .................................................................................. 78
ALEXANDER SCHAVKAN1, FABIAN WESTERMEIER1, BIRGIT FISCHER1, ALESSANDRO RICCI1, MARTIN SCHROER1, GERHARD
GRÜBEL1, MICHAEL SPRUNG1 ............................................................................................................................................... 78
TWO GROUND STATES IN MIXED IN MIXED MN1-XFEXGE COMPOUNDS........................................................... 80
S.-A. SIEGFRIED1, N. M. POTAPOVA2, E. V. ALTENBAYEV2,3, V.A. DYADKIN4,2, E. V. MOSKVIN2,3, V. DIMITRIEV4, D.
MENZEL5, C. D. DEWHURST6, D. CHERNYSHOV4, R. A. SADYKOV7,8, L.N. FORMICHEVA7, A. V. TSVYASHCHENKO7, D.
LOTT1, A. SCHREYER1 AND S. V. GRIGORIEV2,3, .................................................................................................................... 80
STUDY OF THE TEMPERATURE DEPENDENCIES IN FERROMAGNETIC INVERTED OPAL-LIKE
STRUCTURES BY THE SQUID-MAGNETOMETRY...................................................................................................... 82
97
I.S. SHISHKIN1, A.A. MISTONOV1, N.A. GRIGORYEVA1, D. MENZEL2, K.S. NAPOLSKII3, N.A. SAPOLETOVA3, A.A. ELISEEV3,
S.V. GRIGORIEV1,4 ................................................................................................................................................................. 82
TRANSVERSE COHERENCE MEASUREMENTS AT P04 BEAMLINE AT PETRA III ........................................... 85
A.SINGER1, P.SKOPINTSEV1,5, J.BACH2, L.MÜLLER1, B.BEYERSDORF2, S.SCHLEITZER1, O.GOROBTSOV1, A.SHABALIN1,
R.KURTA1, D.DZHIGAEV1,6, O.M.YEFANOV1, L.GLASER1, A.SAKDINAWAT3, Y.LIU4, D.ATTWOOD4, G.GRÜBEL1,
R.FROMTER2, H.P.OEPEN2, J.VIEFHAUS1, I.A.VARTANYANTS1,6 ........................................................................................... 85
SPATIALLY RESOLVED ORIENTATIONAL ORDER IN BINARY COLLOID FILMS STUDIED BY NANOBEAM X-RAY CROSS CORRELATION ANALYSIS....................................................................................................... 88
MARTIN A. SCHROER1, CHRISTIAN GUTT1, FELIX LEHMKÜHLER1, BIRGIT FISCHER1, INGO STEINKE1, ALESSANDRO RICCI1,
FABIAN WESTERMEIER1, SEBASTIAN KALBFLEISCH2, MICHAEL SPRUNG1, GERHARD GRÜBEL1 ........................................... 88
ADIABATICALLY FOCUSING LENSES........................................................................................................................... 90
M. SCHOLZ*1, J. PATOMMEL1, S. HÖNIG1, S. RITTER1, A. JAHN2, C. RICHTER2, J. W. BARTHA2,U. BÖSENBERG3, G.
FALKENBERG3 AND C. G. SCHROER1 ..................................................................................................................................... 90
FIELD INDUCED CHIRALITY IN HELIX STRUCTURE OF MAGNET/NONMAGNET MULTILAYERS........... 91
V. TARNAVICH1, D. LOTT2, S. MATTAUCH3, V. KAPAKLIS4, S. GRIGORIEV1,5 ........................................................................ 91
STRUCTURAL INVESTIGATION OF GLASSES WITH MAGNETIC NANOPRECIPITATES ............................... 92
N.N. TROFIMOVA, 1I.S. EDELMAN,2 O.S. IVANOVA,2 R.D. IVANTSOV,2 E.A. PETRAKOVSKAJA,2 D.A. VELIKANOV,2 V.N.
ZABLUDA,2 AND Y.V. ZUBAVICHUS2 ..................................................................................................................................... 92
FLUORESCENCE PROPERTIES OF CDSE/CDS NANORODS ON GOLD NANOPARTICLES.............................. 94
WIEBKE FRIEDRICH1, KATHRIN HOPPE1, AND HORST WELLER1 ............................................................................................ 94
98

Book of abstracts - RACIRI Summer School 2016

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