Regensburg 2010 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 13: Poster II: Electrical, mechanical and optical properties, nonlinear dielectrics
DF 13.9: Poster
Mittwoch, 24. März 2010, 15:00–17:30, Poster A
Ab initio study of phonons in BaTiO3 — •Pavel Ignatiev and Valery Stepanyuk — Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany
Ferroelectric BaTiO3 ceramic is a very important technological material. Its structure, however, can be different from the perovskites ideal cubic phase. Depending on temperature BaTiO3 can turn to rhombohedral, orthorhombic, tetragonal, cubic and even hexagonal phases. Here we present an ab initio study of various phases of BaTiO3. We report on the optimized lattice parameters, electronic structure and phonons. Ab initio calculations are performed by means of the density functional theory implemented in Quantum Espresso package [1]. Phonons are calculated using the density functional perturbation theory [2]. Polarization-induced LO/TO splitting of phonon branches and Born effective charge tensors are obtained from the first principles using modern polarization theory.
[1] P. Giannozzi et al., J. Phys.: Condens. Matter 21, 395502 (2009).
[2] S. Baroni, S. de Gironcoli, A. Dal Corso, and P. Giannozzi, Rev. Mod. Phys. 73, 515 (2001).