Electronic, magnetic and dielectric properties of multiferroic MnTiO 3

The ground-state structural, electronic, magnetic, optical and dielectric properties of MnTiO 3 are calculated using density functional theory within the generalized gradient approximation. The structure parameters obtained agree well with experimental results. The electronic structure results show that the G-type antiferromagnetic phase of LN-type MnTiO 3 has an indirect band gap of 0.85 eV. The calculated local magnetic moment of Mn ion is 4.19 μ B . The calculated Born effective charges (BECs, denoted by tensor Z * ) show that the Z * of Ti and O atoms are significantly and anomalously large. Interestingly, ferroelectric spontaneous polarization of large magnitude is predicted to be along [111] direction with a magnitude of 87.95–105.22 μC/cm 2 . B-site Ti ions in 3 d 0 state dominate ferroelectric polarization of multiferroic MnTiO 3 , whereas A-site Mn ions having partially filled 3 d 5 orbitals are considered to contribute to its antiferromagnetic properties. Furthermore, it is predicted that multiferroic MnTiO 3 shows good dielectric and optical properties.