Promising half-metallic ferromagnetism in double perovskites Ba _2VTO _6 (T=Nb and Mo): Ab-initio LMTO-ASA investigations

摘要

The electronic and magnetic properties of new ordered vanadium-based double perovskite oxides Ba _2VTO _6 (T=Nb and Mo) have been investigated using the ab-initio linear muffin-tin orbitals method with the atomic-sphere approximation (LMTO-ASA). The calculations performed by using the local spin-density approximation with on-site Coulomb interaction (LSDAU) style. The self-consistent band structure calculations predict half-metallic ferromagnetic (HM-FM) ground states with total spin magnetic moments of 2.1021 μ _B and 3.0633 μ _B per formula unit cell for Ba _2VNbO _6 and Ba _2VMoO _6, respectively. HM-FM nature in two compounds organizes from the ddp _π- superexchange interactions 3d-t _(2g) ~2-O (2p)-4d-t _(2g) ~n (n=0 or 1), conformity with Zener-Goodenough-Kanamori rules.