Theoretical study on anti-site defects in half-metallic zinc-blende ferromagnets

Abstract Effects of anti-site defects in a half-metallic ferromagnet, zinc-blende CrAs, on its electronic and magnetic properties are studied theoretically based on the first-principles band-structure calculations. The magnetic moment of the anti-site Cr atom is coupled anti-ferromagnetically with that of the Cr atom at the ordinary-site, while the ferromagnetic coupling between the Cr moments at the ordinary-sites is robust against the formation of the anti-site defects. The formation of the impurity-bands in the energy gap of the minority-spin states degrades the degree of the spin-polarization at the Fermi-level.