Theoretical Investigations of Structural and Magnetic Ground State Stability of BiMnO3

We investigate the crystal structure and magnetic ground state of monoclinic BiMnO3 using first principles calculations, in order to shed some light on the long standing issues related to the structural stability and ferroelectric polarization of BiMnO3. Our total energy calculations based on full structural optimization reveals that BiMnO3 stabilizes to monoclinic C2/c (centrosymmetric) with ferromagnetic ground state. Furthermore, to validate model calculations report, in which antiferromagnetic ordering is assumed to co-exist with ferromagnetism, to drive ferroelectric polarization, we invoke antiferromagnetic ordering in our calculations and find that this ordering indeed breaks the inversion symmetry and induces ferroelectric polarization along x-z plane.