Cr掺杂4H-SiC电子结构的第一性原理计算  

Electronic Structures of Cr-Boped 4H-SiC by First Principle Calculation

作　　者：林龙[1,2] 刘铁铮[1] 陶华龙[1] 张志华[1] 

机构地区：[1]大连交通大学材料科学与工程学院,辽宁大连116028 [2]河南理工大学数学与信息科学学院,河南焦作454003

出　　处：《大连交通大学学报》2015年第4期80-83,共4页Journal of Dalian Jiaotong University

基　　金：国家自然科学基金资助项目(51372027)

摘　　要：通过第一性原理计算研究了Cr掺杂4H-SiC电子结构和磁性.计算结果表明Cr掺杂引入空穴,产生自旋极化,Cr原子提供局域磁矩.计算了14种可能的掺杂组态,确定了最稳定的组态.磁耦合计算表明Cr原子磁矩通过Cr0:3d-C∶2p-Cr1∶3d链耦合,处于铁磁基态.Cr掺杂4H-SiC体系的铁磁机理是空穴作为载流子的双交换机制,C与Cr原子间强烈的p-d轨道间杂化作为铁磁交换的媒介.Electronic structures and magnetic properties of Cr-doped 4H silicon carbide are studied by first principle calculations. The results indicate that Cr dopant introduces spin-polarized hole states in the band gap,thus the system generates local magnetic moment by the doped Cr atoms. Several doping configurations are studied,and the results suggest the existence of ferromagnetic coupling between Cr dopants. The ferromagnetism mechanism in the Cr-doped 4H-SiC can be attributed to the hole-mediated double exchange through the strong p-d interaction between C and Cr.

关 键 词：稀磁半导体 电子结构 磁性 第一性原理 4H-SIC 

分 类 号：O47[理学—半导体物理] O483[理学—物理]