Electroresistance in ferroelectric tunnel junctions
Josep Fontcuberta1,*, Greta Radaelli1,2, Diego Gutierrez1, Jaap Geessinck1, Mengdi Qian1, Florencio
Sánchez1, Ignasi Fina3, Riccardo Bertacco4
Institut de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB.
Carrer dels Til·lers sn. Bellaterra 08193. Catalonia. Spain
Istituto Italiano di Tecnologia, Smart Materials – Nanophysics Department,
Via Morego 30, 16163, Genoa, Italy.
Max Planck Inst. of Microstructure Physics,
Weinberg 2, D-06120 Halle/Saale, Germany
LNESS - Dipartimento di Fisica, Politecnico di Milano,
Via Anzani 42, 22100 Como. Italy
*e-mail: [email protected]
Ferroelectric (FE) polarization (P) can modulate the electric conductance in metal-FE-metal junctions by a
number of reasons. The tunnel electroresistance effect is understood as due to the change of the barrier
height upon polarization reversal in presence of asymmetric electrodes. However, pure interface effects and
strain (piezo) effects may also contribute to barrier modification.
These considerations apply when the metal electrodes are robust good metals, whose properties do not
change appreciably upon charge accumulation or depletion as it occurs when the metal electrodes are
sandwiching and screening polarization charges of a ferroelectric tunnel barrier. However, some metallic
materials display metal-insulator transitions upon tiny changes of the carrier concentration, thus offering an
alternative way to tune the barrier width upon polarization reversal by driving these poor metals into the
insulating/metal state. The La1-xAxMnO3 (A= Sr, Ca) manganites are the most popular bottom electrodes
being used for FE tunnel junctions and for some particular compositions, are example of this behavior; they
could be eventually used to engineer the barrier properties and to modify the barrier properties.
Here, we will review some recent results on FE tunnel junctions fabricated either using optimally doped
La2/3Sr1/3MnO3 electrodes or La1/2Sr1/2(Ca1/2)MnO3 electrodes with a hole concentration close to the metalinsulator transition, with focus on understanding the roles of the semiconducting properties of the BaTiO3
layer and the electrodes on the TER response of the junctions.
Greta Radaelli et al., Adv. Mater. 2015 in press
Laboratory of Multifunctional Oxides and Complex Structures
Phone: +34 93 580 18 53 (ext 228)
Institut de Ciència de Materials de Barcelona (ICMAB-CSIC)
Carrer dels Til·lers s/n. Campus de la UAB, 08193 Bellaterra, Barcelona, SPAIN
PLACE AND DATE OF BIRTH:
ÍCAR & AMARANTA
Teacher and Lecturing
Professor of Condensed Matter, Physics Fac., University Barcelona
Assistant Professor on Nuclear Physics, Phys. Fac, University Barcelona,
Assistant Professor on Solid State Physics. Phys. Fac., University Barcelona,
Assistant Professor on Crystallography, Chemistry Fac., University Barcelona,
Assistant Professor on Crystallochemistry, Geology Fac., University Barcelona,
Research Professor ICMAB-CSIC
Tenured Researcher ICMAB-CSIC
Ph.D. in Physics, Universitat de Barcelona, Spain
M.Sc. in Physics, Universitat de Barcelona
1982 - 1990
1980 - 1982
1978 - 1980
1977 - 1978
1977 - 1977
CURRENT RESEARCH INTERESTS:
All along my scientific carrier I have been mostly interested on functional oxides. These strongly correlated
electronic systems display fascinating properties such as ferroic (i.e. magnetic, ferroelectric), electric, optic,
etc, that have motivated my research and that of the group I’m leading. I’m a material’s scientist and I have
devoted much effort to the preparation and epitaxial growth of complex oxides and heterostructures and to
the study of the relationship between structure, microstructure and functional properties. Nowadays, my
research activity is focused on materials and devices for magnetoelectronics. I’m persuaded that oxides may
play a very important role in advanced high-tech devices and thus, in all projects I have bee involved and
steered I have pushed for the development of either new applications or new-concept devices aiming to
exploit functional properties of oxides.
I’m co-author of more than 350 peer-reviewed scientific papers (including Nature Materials, Adv. Mat., Phys.
Rev. Lett, Appl. Phys.Lett, etc) and supervised 20 PhD Thesis works. I have delivered more than 100 Invited
Talks at Workshops and Conferences. I’m co-author of several patents and I have participated in some U.E.
scientific projects (STREPS, Networks, Marie-Curie Training site, etc) and ESF and NATO projects related to the
advanced of thin film technologies of magnetic and multiferroic oxides.
Editor of Solid State Communications, Scientific Journal (Elsevier)
Advisory Board of Journal of Magnetism and Magnetic Materials (Elsevier)
Advisory Board of Advanced Electronic Materials (Wiley –VCH)
Member of Evaluation Panels of several Laboratories of various European Countries.
Project Technical Assistant (PTA) of the NMP program of the UE (FP7)
SCIENCE AND SOCIETY INTERESTS: I am very much interested on learning and disseminating physics in daily life.
I’m much concerned by both local and global geopolitical situation and I have travelled to quite remote areas