Magnetic properties of 3d transition metal atoms (V, Cr, Mn, Fe, Co or Ni) doped Mg ₂ Si

The magnetic properties of Mg2Si-based dilute magnetic semiconductors in Mg62X2Si32 systems (X = V, Cr, Mn, Fe, Co, and Ni) are investigated by spin-polarized first-principle calculations. The ground-state magnetic interaction of V-, Cr-, or Fe-doped Mg2Si system is ferromagnetic (FM) coupling, consistent with the double-exchange mechanism. The Mn- or Co-doped Mg2Si system is antiferromagnetic (AFM) coupling, which can be explained by the superexchange mechanism. The ground state of Ni-doped Mg2Si is the nonspin-polarized state. The V- or Cr-doped Mg2Si exhibits half-metallic character, Mn- or Co-doped Mg2Si is a semiconductor, and Fe-doped Mg2Si presents metallic nature. It can be seen that different 3d transition metal atom-doped Mg2Si correspond to different potential applications.