LMTO-ASA electronic and magnetic structures calculations of the (3d–5d) mixed double perovskite oxides Ba2BB'O6 (BB'=V-Hf, Cr-Ta, Mn-W)

Abstract

The electronic and magnetic structures of series of double perovskite oxides Ba2BB'O6, have been calculated by using the ab-initio linear muffin-tin orbital method with the atomic-sphere approximation (LMTO-ASA). The calculations were performed using the local spin density approximation with the coulomb interaction method (LSDA+U) in the framework of density functional theory (DFT). The results show that Ba2VHfO6 is half-metallic and Ba2CrTaO6 is conductor. The conduction bands in two compounds form mainly from the contributions of V (3d) and Cr (3d) elements. Ba2MnWO6 was found to be semiconductor, agreement with the results of J. Cheng and Z. Q. Yang. The ground magnetic phases for the first two compounds were found to be ferromagnetic while, the third was found to be antiferromagnetic material. These caused the hybridization between the V/Cr (3d) t2g spin up and Hf/Ta (5d) t2g spin up, and between Mn (3d) t2g spin up and W (5d) t2g spin down orbitals. The magnetic moments were found to be 1.39 μB for V4+, 0.35 μB for Hf4+, 2.79 μB for Cr3+, -0.46 μB for Ta5+, 4.41 μB for Mn2+ and -0.42 μB for W6+.