First-principle investigation on electronic structure, magnetism and multiferroicity of BiMn3Fe4O12

The lattice parameters, electronic structure, magnetism and multiferroicity of compound BiMn3Fe4O12 were investigated by using the first-principle calculations. The total energy calculations indicated that BiMn3Fe4O12 was a G-type antiferromagnetic insulator. The ferroelectricity was induced by magnetism and originated from the hybridization between Fe and Mn ions. The electric polarization was predicted to be around 39 μC/m2 along 〈1 1 1〉 orientation. It was sensitive to the lattice distortion such as Fe ion shift of FeO6 octahedron and a great improvement in electric polarization could be possibly achieved by strain engineering or inducing chemical pressure. Furthermore, the effects of on-site Coulomb repulsion on electronic structure, magnetism, and ferroelectricity were also discussed. It was showed that with increasing U the spin splitting increased, resulting in an increased ban-gap and hybridization between Fe and Mn ions, and then electric polarization.