Structural stability and half-metallic ferromagnetism in PbMoO3: The role of electronic correlation

Abstract

We theoretically investigate the electronic and magnetic properties of the recently reported cubic and orthorhombically (Ortho.) distorted phases of PbMoO3, a 4d transition-metal perovskite oxide with almost half-filled t2g states. Our spin-polarized bare generalized gradient approximation results exhibit that the cubic phase is of low energy structure than the Ortho. one. However, on-site Coulomb repulsion in the range of 3.3 eV ≤ Ueff ≤ 4.5 eV inclusion on Mo 4d orbitals reveals that at each value of Ueff, the Ortho. phase is more stable than the cubic one and with the increase in Ueff, both phases show more stability. We find a non-magnetic n-type conductivity with a high charge carrier density of ∼1022 cm−3 in both phases. Interestingly, a non-magnetic to magnetic phase transition occurs at Ueff = 3.8 eV and 3.5 eV for the cubic and Ortho. phases, respectively. Moreover, a half-metallic ferromagnetic state is obtained at Ueff = 4.1 eV and 4.3 eV for the cubic and Ortho. phases, respectively. Calculations also indicate a strong orbital hybridization between Pb 6p and Mo 4d, with a significant contribution of O 2p states. All findings are confirmed by the Yukawa screened Perdew-Burke-Ernzerhof 0 (YS-PBE0) hybrid functional. This work provokes further experimental investigations of magnetic properties of PbMoO3.