First principles materials design for semiconductor spintronics

Materials design of new functional diluted magnetic semiconductors (DMSs) is presented based on first principles calculations. The stability of the ferromagnetic state in ZnO-, ZnS-, ZnSe-, ZnTe-, GaAs- and GaN-based DMSs is investigated systematically and it is suggested that V- or Cr-doped ZnO, ZnS, ZnSe and ZnTe are candidates for high-T_C ferromagnetic DMSs. V-, Cr- or Mn-doped GaAs and GaN are also candidates for high-T_C ferromagnets. It is also shown that Fe-, Co- or Ni-doped ZnO is ferromagnetic. In particular, the carrier-induced ferromagnetism in ZnO-based DMSs is investigated and it is found that their magnetic states are controllable by changing the carrier density. The origin of the ferromagnetism in the DMSs is also discussed.