Electronic and magnetic properties of 3d transition-metal-doped II-IV-V-2 chalcopyrite semiconductor

A systematic study based on ab initio calculation within local spin density appr oximation is carried out for material design of Ⅱ-Ⅳ-Ⅴ2 2 chal copyrite semiconductor (CdGeP2 2 and ZnGeP2 2 ) doped with 3d-TM (TM= V, Cr, Mn, Fe, Co and Ni). It is found that the ferromagnetic (FM) state will be realized in V and Cr doped CdGeP2 2 and ZnGeP2 2 ; for Mn, Fe and Co doped ones, the antiferromagnetic (AFM) states are more stable than FM states; whereas dope d with Ni, the dilute magnetic semiconductor (DMS) shows unstable ferromagnetism . It is suggested that Ⅰ-Ⅳ-Ⅴ2 2 chalcopyrite semiconductor doped with Cr is a candidate for high Curie temperature (TC C ) DMS. When th e t2g 2g states of TM are partially occupied, the DMS doped with TMs shows a stable FM state, whereas when the t2g 2g states of TMs are fully occupied or empty, the DMS with the TM shows AFM state. In order to elucid ate the underlying mechanism of the ferromagnetism in DMS, the magnetism in (C d,Mn)GeP2 2 and (Cd,Mn)GeP2 2 under the carrier (elect ron or hole) doping treatment is investigated. It is found that it is crucial to realize the carrier-induced ferromagnetism, indopendent of whethe r the doped carrier has itinerant TM-3d character or not.