摘要
采用基于密度泛函理论的第一性原理平面波赝势方法研究Co掺杂4H-SiC的电子结构和磁性。计算结果表明:Co掺杂引入了空穴,产生自旋极化。Co掺杂4H-SiC的价带顶和导带底分别由Co的3d态和C的2p态占据,而Si的2p轨道作用较小。通过计算10种可能的掺杂位置,确定了铁磁性最稳定的组态。由于Co_0:3d-C:2p-Co_6:3d链之间存在一定的耦合关系,Co与C原子间强烈的d-p轨道杂化使得Co掺杂4H-SiC处于较稳定的铁磁基态。Co的引入使得基体空穴增加,缺陷调节下空穴载流子的远程交换(RKKY)机制导致了铁磁性的出现。
Electronic and magnetic properties of Co doped 4H-SiC are researched by use of the first-principle plane wave pseudo-potential method based on density functional theory. Ten kinds of doping position were calculated and the most stable configuration was found out. The calculation results show that spin-polarization appears in one Co atom doped 4H-SiC, which is due to the introduction of vacancy. The top of valence band and the bottom of the conduction band are mainly contributed by Co-3 d, C-2 p orbitals, with small contribution of Si-2 p. Ferromagnetism order is activated by Co doping via a Co0：3 d-C：2 p-Co6：3 d coupling chain. Hybridization occurs between p-d orbitals. The doped Co ion will induce additional holes carrier into the 4H-SiC. Therefore, the mechanisms for stabilizing the ferromagnetic state in Co doped 4H-SiC based on defect interaction and Ruderman-Kittel-Kasuya-Yosida（RKKY） interaction.
作者
林龙
祝令豪
李先宏
张志华
何明
陶华龙
徐永豪
张战营
曹建亮
LIN Long;Zhu Ling-hao;LI Xian-hongl;ZHANG Zhi-hua;He Ming;TAO Hua-long;XU Yong-hao;ZHANG Zhan-ying;CAO Jian-liang(Cultivating Base for Key Laboratory of Environment-Friendly Inorganic Materials in Henan Province, School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China;Liaoning Key Materials Laboratory for Railway, School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, China;School of Physics ＆ Electronic Information Engineering, Henan Polytechnic University, Jiaozuo 454000, Chin)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2017年第10期2114-2119,共6页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(51172065
51372027
51372026
51372056)~~
关键词
稀磁性半导体
电子结构
磁性
第一性原理
4H-SIC
dilute magnetic semiconductors
electronic structure
magnetism
first principle
4H-SiC
