First principles study of the effects of disorder in the Sr2FeMoO6 perovskite

First principles calculations were done in the double perovskite Sr2FeMoO6 regarding the effects of cationic disorder and electronic correlation in the ground-state properties such as spin polarization and magnetic saturation. We used the Generalized Gradient Approximation (GGA) method including a U Hubbard term. Results with 25% of disorder, where Fe-O-Fe and Mo-O-Mo configurations frequently occur, are shown. We found that disorder breaks down the half-metallic ferromagnetic behavior. We also calculated a magnetic saturation decrease from 4.0 mu(B) per formula unit to 2.22 mu(B) in accord with neutron magnetic scattering experiments.