An ab initio study of electronic structure and optical properties of multiferroic perovskites PbVO3 and BiCoO3

摘要: Within density functional theory (DFT) with the generalized gradient approximation (GGA), GGA plus onsite Coulomb repulsion method, and improved version of modified Becke–Johnson exchange potential suggested recently by Tran Blaha [F. Tran, P. Blaha, Phys. Rev. Lett. 102 (2009) 226401] (TB–mBJ), we investigate electronic structure optical properties noncentrosymmetric multiferroic perovskites PbVO3 BiCoO3. These two compounds, although similar in lattice distortions population crystal-field levels, behave quite differently because different interplay between fundamental Kramers degeneracy single-ion anisotropy them. The main characteristic calculated TB– mBJ structures is significant rearrangement V Co 3d states near their valence bands tops when compared to present earlier + U calculations these compounds. This fact causes responses title compounds as well, which are analyzed interpreted terms structures. A comparison available experimental data indicates that TB–mBJ approach provides a better description BiCoO3 than standard approaches. 2013 Elsevier B.V. All rights reserved.