Ab initio study on Pb_2FeOsO_6 and possible half metallicity via Na doping

摘要

Pb2FeOsO6, with an Fe-Os antisite occupancy of about 16%, was synthesized recently and measured to be a cubic ferrimagnetic semiconductor with a high magnetic ordering temperature (T-c) of 280 K. We performed an investigation on Pb2FeOsO6 by using the density functional theory. Our calculated results indicate that Pb2FeOsO6 crystallizes into tetragonal symmetry and is a C-type antiferromagnet. After doping with Na, the system experiences a transition from C-type antiferromagnetic state to ferrimagnetic state, and the half-filled Os5+ t(2g) orbitals cross the Fermi level owning to the injection of holes. Therefore, the Na-doped Pb2FeOsO6 exhibits a half metallic nature. Moreover, the T-c raises significantly by Na doping. Therefore, we expect that the Na-doped Pb2FeOsO6 would be promising candidates as spintronic material.