The influence of the M (3d) replacement on structural, electronic and magnetic properties of Nb-based double perovskite Ba2MNbO6 (M = Sc, Ti, V and Cr): From FP-LMTO studies

Employing the self-consistent full-potential linear muffin-tin orbital (FP-LMTO) computational method, systematic studies have been performed on the influence of M (3d) replacement on structural, electronic and magnetic properties of novel Nb-based barium double perovskite Ba2MNbO6 (M (3d) = Sc, Ti, V and Cr). The crystal structure calculations show that the Ba2MNbO6 structures are in face-centered cubic with a space group (Fm-3m). The band structure calculations have been performed using the correlated local spin density approximation (LSDA+U). The results showed that Ba2TiNbO6 and Ba2VNbO6 are half-metallic ferromagnetic materials in ground states, having energy-gaps in the spin-down bands and finite densities of states in the spin-up bands. While an insulating and ferromagnetic behaviors were obtained in Ba2ScNbO6 and Ba2CrNbO6. It is found that the M3+ (3d- t 2 g n ) ions (0 ⩽ n ⩽ 3) have major influence, while the nonmagnetic Nb5+ (4d- t 2 g 0 ) ions have minor effect, on electronic conducting and magnetic moment in Ba2MNbO6.