First principle study on structural, elastic and electronic properties of cubic BiFeO3

We present the first principle studies of the structural and electronic properties in high temperature cubic phase (Pm3m) of BiFeO3 based on Density Functional Theory (DFT). All calculations are performed within Local Density Approximation (LDA) functional and Generalized Gradient Approximation (GGA) functional with Ultrasoft Pseudopotentials (USP). It shows that the calculated structural parameters of cubic BiFeO3 are in a good agreement with previous literatures. Based on the calculated of elastic properties of cubic BiFeO3, this material shows a stable mechanical structure. In electronic band structure, the electron wave propagates through Brillouin zone X–R–M–G–R points where the highest valence band overlap with the lowest conduction band to give zero energy band gaps. The Density of States (DOS) demonstrated the significant hybridization between Bi6p, Fe3d and O2p in the range of −5 eV–5 eV. Thus, it can be implied that multiferroic BiFeO3 are metallic at cubic phase and the metal–insulator transition in this material obeys the band theory.