Berlin 2008 – wissenschaftliches Programm

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SYNF: Symposium Ferroic materials and novel functionalities

SYNF 1: Ferroic materials and novel functionalities I

SYNF 1.4: Vortrag

Dienstag, 26. Februar 2008, 11:15–11:30, A 151

Influence of polarization on the surface relaxation of perovskite ferroelectrics — •Michael Fechner, Ostanin Sergey, and Ingrid Mertig — Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Saale), Germany

Ferroelectric materials exhibit a electric polarization which is spontaneous and switchable by an electric field. These materials become important due to their possible application in multiferroic materials. In our study we investigate clean (001) surfaces of FE perovskites from first principles. We consider three different systems which are SrTiO₃, BaTiO3, and PbTiO3. These compounds differ in their size of spontaneous polarization from zero (SrTiO₃) to moderate (BaTiO₃) to high values (PbTiO₃). Due to this we could investigate the surface relaxation and electronic properties with respect to the size and the direction of the spontaneous polarization. Latter is done by considering the cases of a polarization direction parallel and antiparallel to the surface normal. In our study it turns out that the direction of polarization at the surface is independently of the polarization in the lower lying layers and the considered material. The results of our study are in good agreement with recent experimental findings [1].

[1] Y. Urakami Ferroelectrics, 346 (2007)