Material Design of Transparent, Half-Metallic and Room-Temperature Ferromagnets in I_2-Ⅵ Semiconductors with 4d Transition Metal Element

摘要

A new class of 4d transition-metal-doped anti-CaF_2 I_2-Ⅵ diluted magnetic semiconductors (DMSs) is presented based on first-principles calculations. We have systematically investigated the stability of the ferromagnetic state in K_2O-, K_2S-, K_2Se-, K_2Te-, Li_2S-, Na_2S- and Rb_2S-based DMSs. Anti-CaF_2 I_2-Ⅵ compounds have a large lattice spacing due to their large ionic radius of cations and many of them are wide-bandgap semiconductors. From the total energy differences between the ferromagnetic state and the spin-glass state, ferromagnetic solutions are derived and it is found that Zr-, Tc- and Ru-doped K_2O, Zr-, Nb-, Tc- and Ru-doped K_2S, and Zr-, Nb-, and Ru-doped K_2Se, K_2Te, and Rb_2S are good candidates for transparent, half-metallic and room-temperature ferromagnetic DMSs with a large magnetoptical effect.