Disorder effect on the electronic and magnetic properties of Sr2FeCoO6: A density-functional theoretical investigation

Using density-functional calculations within the generalized gradient approximation plus U framework, the electronic and magnetic properties of the ordered and the disordered Sr2FeCoO6 are investigated systematically. The results show that all disordered Sr2FeCoO6 have ferromagnetic ground state, as that of the ordered one. The magnetic coupling of both Fe and Co sublattices remains ferromagnetic, and the two sublattices are coupled ferromagnetically as well. Most interestingly, the disorder leads to the substantial increase of the magnetic moments on both Fe and Co sites comparing with those of the ordered Sr2FeCoO6. It is also significantly found that the disorder can control the transport property, decreasing the half-metallic band gap of the ordered Sr2FeCoO6 and even giving rise to a half-metal to metal transition at a critical level of disorder. (C) 2011 American Institute of Physics. [doi:10.1063/1.3653238]