Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 100: Resistive Switching I (jointly with DS, DF, KR)

HL 100.1: Vortrag

Freitag, 30. März 2012, 09:30–09:45, H 0111

Ab-initio studies of metal-insulator transitions in defective perovskites — •Gustav Bihlmayer and Kourosh Rahmanizadeh — Peter Grünberg Institut & Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

Resistive switching in perovskite materials can be triggered by a variety of external stimuli, like electric fields or oxygen partial pressure. While the role of oxygen defects for the electronic transport is in many cases established, the nature of the metal-insulator transition has still to be explored. Density functional theory calculations including strong correlation effects on a model level can help to gain an understanding here.

We investigate the transition between an insulating state of a correlated, localized level and a partially filled conductive band as function of electron concentration. The band filling can be controlled in a chemical way or via electric fields. A ferroelectric polarization can screen or enhance the effects at the boundaries of a ferroelectric material. We study the localization of defect states in model systems of structurally simple perovskites like SrTiO₃ or PbTiO₃ to gain a coherent picture of the conductive states that are manipulated in the resistive switching process.

Financial support of the EU grant NMP3-LA-2010-246102 (IFOX) is gratefully acknowledged.