Band-structure calculations of imperfect Co2MnGe Heusler compounds

The effect of imperfections on the bandstructure of Co2MnGe is explored. In particular, the effect of uniform and tetragonal distortions, and Cu, Al, O, Rh, and Sn impurities on the half-metallic behavior are examined. We find that a high spin polarization can be maintained even under significant strains and distortions. However, we find that impurities with as little as 3% concentration will generally have a significant detrimental effect on the half-metallic behavior of the Heusler alloy.