Effects of disorder in the Sr$_{\mathrm{2}}$FeMoO$_{\mathrm{6\thinspace }}$double perovskite via first principles calculations.

First principles calculations were done in the double perovskite Sr$_{\mathrm{2}}$FeMoO$_{\mathrm{6}}$ regarding the effects of cationic disorder and electronic correlation in the ground-state properties such as spin polarization and magnetic moment. We used the Generalized Gradient Approximation (GGA) method including a U Hubbard term. Disorder is introduced via atomic substitution with a ratio of 25{\%} and 12.5{\%}. It is found a magnetic saturation of 2.22\textmu $_{\mathrm{B}}$ and 2.99\textmu $_{\mathrm{B}}$ for 25{\%} and 12.5{\%} of disorder respectively, in agreement with neutron magnetic scattering experiments. The half-metallic behavior of the above double perovskite remains only for a 12.5{\%} of disorder.