Insulator-half metal transition driven by hole doping: a density functional study of Sr-doped La_2VMnO_6

摘要

La_2VMnO_6 is an insulating ferrimagnet experimentally. By substituting La with Sr, La_(2-x)Sr_xVMnO_6 (x = 0.5, 1.0, 1.5, 2.0) was investigated using the density functional theory. Our results indicated that half metallic properties are obtained for x = 0.5, 1.5, 2.0. For x = 1.0, it is insulating.With the increase of hole doping, the holes initially go to V 3d orbitals for x = 0.5, 1.0, and after that, the holes go to the Mn 3d orbitals for x = 1.5, 2.0. Ferrimagnetic coupling between V and Mn is found to be the ground state for x = 0.5, 1.5, while for x = 1.0 and 2.0, ferromagnetic and antiferromagnetic couplings between Mn and Mn are competitive for the ground state.