MtPh

Quasi-two-dimensional electron gas at the ferroelectric/dielectric interface

date
24.04.2018 
time
11:00 AM - 12:00 PM 
speaker
Dr. Rinat Mamin 
affiliation
Zavoisky Physical-Technical Institute, RAS Kazan, Russia 
language
en 
main topic
Materials: Superconductors, Magnetic Materials, Nano Structures
subtopics
Physics: Condensed Matter (incl. Soft, Solid)
host
Christine Malbrich 
abstract

Abstract

A high-mobility electron gas was first observed in 2004 at the interface of heterostructure involving LaAlO3 (LAO) and SrTiO3 (STO). After that, such heterointerfaces involving two insulating nonmagnetic oxides were comprehensively studied. In particular, it was found that the metallic phase (quasi-two-dimensional electron gas, 2DEG) is formed in the STO layers at the LAO/STO interface when the number of LAO layers is larger than three. Such a system undergoes a transition to a superconducting state at temperatures below 300 mK.
We investigate the properties of 2DEG at the interface between ferroelectric oxide and insulating oxide in heterostructures, isostructural to BaTiO3/LaMnO3. The temperature dependence of the electrical resistance has been studied for heterostructures formed by antiferromagnetic LaMnO3 single crystals of different orientations with epitaxial films of ferroelectric Ba0.8Sr0.2TiO3 (BSTO) deposited onto them. The measured electrical resistance is compared to that exhibited by LaMnO3 (LMO) single crystals without the films. It is found that, in the samples with the film, for which the axis of polarization in the ferroelectric is directed along the perpendicular to the surface of the single crystal, the electrical resistance decreases significantly with temperature, exhibiting metallic behavior below 160 K. The numerical simulations of the structural and electronic characteristics of the BaTiO3/LaMnO3 ferroelectric-antiferromagnet heterostructure have been performed. The transition to the state with 2DEG at the interface is demonstrated. The effect of a magnetic field on heterostructure BSTO/LMO haves been investigated. It is sown that magnetic field change the resistivity properties of the interface BSTO/LMO very strong. The new properties of the interfaces of some other heterostrocture will have been presented.

 

Last update: 24.04.2018 07:59.

venue 

Leibniz Institut für Festkörper- und Werkstoffforschung Dresden (B3E.26, IFW Dresden) 
Helmholtzstraße 20
01069 Dresden
homepage
http://www.ifw-dresden.de 

organizer 

Leibniz Institut für Festkörper- und Werkstoffforschung Dresden (IFW)
Helmholtzstraße 20
01069 Dresden
homepage
http://www.ifw-dresden.de 
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