Pseudo-half-metallicity in the double perovskite Sr2CrReO6 from density-functional calculations

The electronic structure of the spintronic material Sr2CrReO6 is studied by means of full-potential linear muffin-tin orbital method. Scalar relativistic calculations predict Sr2CrReO6 to be half-metallic with a magnetic moment of 1μB. When spin–orbit coupling is included, the half-metallic gap closes into a pseudo-gap, and an unquenched rhenium orbital moment appears, resulting in a significant increase of the total magnetic moment to 1.28μB. This moment is significantly larger than the experimental moment of 0.9μB. A possible explanation of this discrepancy is that the anti-site disorder in Sr2CrReO6 is significantly larger than hitherto assumed.