Prediction of large polar Kerr rotation in the Heusler-related alloys AuMnSb and AuMnSn

Theoretical spectra for the magneto-optical Kerr effect have been obtained for the Heusler-related alloys AuMnSb and AuMnSn, and repeated calculations are performed for the isostructural PtMnSb phase. Using experimental lattice constants, our calculations predict a Kerr rotation exceeding −1° in the 0.5–0.8 eV region for AuMnSb and a somewhat smaller rotation for AuMnSn. Supercell calculations indicate that half-metallic behavior can be induced on hole/electron doping in the AuMnSn1−xSbx solid-solution phase for 0.50