Insulator-half metal transition driven by M-site doping in double perovskite Ba2CrMO6 (M = Nb, Mo) from first-principles calculations

Abstract

The structural, electronic and magnetic properties of double perovskite Ba2CrMO6 (M = Nb, Mo) and how it is influenced by elctron doping are investigated systemically by first principles calculations. We find, on consideration of both the electron correlation (LSDA+U) and spin orbital coupling (SOC) effects, that the Ba2CrMO6 takes an imsulating nature, yet is transformed to half-metallicity once an elctron doping from M = Nb to M = Mo is introduced. Such tuning is accompanied by a spin-state transition of M 5+ from empty spin-state in Nb 5+ (t2g 0 eg 0 ) to occupied spin-state in Mo 5+ (t2g 1 eg 0 ). Results show that the doped electron occupies chiefly the down spin orbitals, and it plays a vital role in determining the electronic and magnetic properties of Ba2CrMO6.