TM掺杂Ⅱ-Ⅳ-Ⅴ_2黄铜矿半导体的电磁性质  

Electronic and magnetic properties of 3d transition-metal-doped Ⅱ-Ⅳ-Ⅴ_2 chalcopyrite semiconductor

作　　者：曾永志[1] 黄美纯[1] 

机构地区：[1]厦门大学物理系,厦门361005

出　　处：《物理学报》2005年第4期1749-1755,共7页Acta Physica Sinica

基　　金：国家自然科学基金 (批准号 :10 2 74946;60 3 3 60 10 )资助的课题~~

摘　　要：利用自旋局域密度泛函的第一性原理对 3d过渡金属 (TM =V ,Cr,Mn ,Fe ,Co和Ni)掺杂的Ⅱ Ⅳ Ⅴ2 (CdGeP2 和ZnGeP2 )黄铜矿半导体的电磁性质进行系统计算 .结果发现 :V和Cr掺杂的CdGeP2 和ZnGeP2 将出现铁磁状态(FM) ,Mn ,Fe以及Co掺杂的CdGeP2 和ZnGeP2 将出现反铁磁状态 (AFM) ,而Ni掺杂时 ,稀磁半导体 (DMS)的磁性比较不稳定 .其中Cr掺杂的CdGeP2 和ZnGeP2 将可能是具有较高居里温度TC 的DMS .当TM 3d电子的t2g态部分被填充时 ,其掺杂的DMS将出现FM状态 ;而当TM 3d电子的t2g态全满或者全空时 ,其掺杂的DMS将出现AFM状态 .在(Cd ,Mn)GeP2 和 (Zn ,Mn)GeP2 中分别掺入电子和空穴载流子 ,可以发现载流子是否具有TM 3d电子的巡游特性是DMS是否出现FM状态的主要原因 .A systematic study based on ab initio calculation within local spin density approximation is carried out for material design of Ⅱ-Ⅳ-Ⅴ 2 chalcopyrite semiconductor (CdGeP 2 and ZnGeP 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 CdGeP 2 and ZnGeP 2; for Mn, Fe and Co doped ones, the antiferromagnetic (AFM) states are more stable than FM states; whereas doped with Ni, the dilute magnetic semiconductor (DMS) shows unstable ferromagnetism. It is suggested that Ⅰ-Ⅳ-Ⅴ 2 chalcopyrite semiconductor doped with Cr is a candidate for high Curie temperature (T C) DMS. When the t 2g states of TM are partially occupied, the DMS doped with TMs shows a stable FM state, whereas when the t 2g states of TMs are fully occupied or empty, the DMS with the TM shows AFM state. In order to elucidate the underlying mechanism of the ferromagnetism in DMS, the magnetism in (Cd,Mn)GeP 2 and (Cd,Mn)GeP 2 under the carrier (electron or hole) doping treatment is investigated. It is found that it is crucial to realize the carrier-induced ferromagnetism, indopendent of whether the doped carrier has itinerant TM-3d character or not.

关 键 词：稀磁半导体 过渡金属 双交换作用 铁磁状态 自旋局域密度泛函 

分 类 号：O472[理学—半导体物理]