First-principles investigation of ferromagnetism and ferroelectricity in bismuth manganite

We present results of local spin density approximation (LSDA) pseudopotenti al calculations for the perovskite structure oxide, bismuth manganite (BiMn O3). The origin of the differences between bismuth manganite and other pero vskite manganites is determined by first calculating total energies and ban d structures of the high symmetry cubic phase, then sequentially lowering t he magnetic and structural symmetry. Our results indicate that covalent bon ding between bismuth cations and oxygen anions stabilizes different magneti c and structural phases compared with the rare earth manganites This is con sistent with recent experimental results showing enhancement of charge orde ring in doped bismuth manganite. [S0163-1829(99)11113-5].