Hyperfine interactions and magnetism of 3d transition-metal-impurities in II-VI and III-V compound-based diluted magnetic semiconductors

The electronic structure of II-VI and III-V compound-based diluted magnetic semiconductors is calculated based on the local density approximation (LDA) using the Korringa-Kohn-Rostoker method combined with the coherent potential approximation. The magnetism of 3d transition-metal-atom-doped ZnO, ZnS, ZnSe, ZnTe, GaN, GaAs is investigated from first-principles. It is suggested that the double exchange mechanism stabilizes the ferromagnetism in these DMSs. In order to obtain microscopic information on the electronic structure of transition-metal-impurities in semiconductors, the hyperfine field of respective impurities in each host material is calculated. It is found that the agreement with the experimental values is not good, probably because the LDA is not sufficient to describe the core states of transition metals. However, it is suggested that the hyperfine fields clearly reflect the local magnetic moments for 3d impurities.