New Class Of High-T-C Diluted Ferromagnetic Semiconductors Based On K2s Without Transition Metal Elements

We propose new-type diluted ferromagnetic semiconductors (DMSs) based on K2S without any transition metal elements. These materials show transparent and half-metallic ferromagnetism if the deep-impurity-band width (W) induced by doping of Si of Ge impurities, and the electron-correlation energy (U) satisfy the Stoner's condition of highly-correlated electron system (U > W). Based on our first-principles calculations, we demonstrate that these materials satisfy the Stoner's condition, and could be new candidates for transparent and half-metallic DMSs.