Berlin 2012 – wissenschaftliches Programm

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DF: Fachverband Dielektrische Festkörper

DF 18: Resistive switching I (jointly with DS, KR, HL)

DF 18.3: Vortrag

Freitag, 30. März 2012, 10:00–10:15, H 0111

A ferroelectric switchable tunnel junction: KNbO₃/SrTiO₃ — •Kourosh Rahmanizadeh, Gustav Bihlmayer, Daniel Wortmann, and Stefan Blügel — Peter Grünberg Institut (PGI-1) & Institute for Advanced Simulation (IAS-1), Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

The properties of thin oxide films and multilayers are strongly influenced by defects and, therefore, can be controllably tuned by the defect concentration at the interface. For example, due to the charge discontinuity at the SrTiO₃/KO-KNbO₃-NbO₂/SrTiO₃ interface only one direction of polarization in KNbO₃ film is stable. A switchable polarization in KNbO₃ can be realized by creating (oxygen) defects at the interfaces.

We carried out density functional theory (DFT) calculations based on the full potential linearized augmented planewave (FLAPW) method as implemented in the FLEUR code [1] for studying the polar interface SrTiO₃/KNbO₃ and a SrRuO₃/SrTiO₃/KNbO₃ tunnel junction. The electronic transport properties of the switchable multiferroic SrRuO₃/SrTiO₃/KO-KNbO₃-NbO₃/SrTiO₃/SrRuO₃ heterostructure have been investigated using an embedded Green-function approach [2]. A strong dependence of the (magneto electric) transport properties on the polarization is observed. The work was conducted under the auspices of the IFOX consortia under grant agreement NMP3-LA-2010-246102.

[1] http://www.flapw.de

[2] D. Wortmann, H. Ishida, and S. Blügel, PRB 66, 075113 (2002)