4H-SiC基稀磁半导体的电子结构

Study of Electronic Structure of 4H-SiC Based Diluted Magnetic Semiconductor

通过第一性原理计算研究3d过渡金属元素(TM)掺杂六方结构碳化硅(4H-SiC)晶体和Al、TM共掺杂4H-SiC晶体的总能和磁学性质.掺杂4H-SiC结构的稳定性取决于TM和Si原子的化学势.结果发现在TM掺杂4H-SiC体系中,掺杂Ti的结构是最稳定的,而Al、TM共掺4H-SiC中掺杂V的结构是最稳定的.对比TM元素单掺杂和Al与TM元素共掺杂体系的磁性质可知,Al有稳定结构和影响结构磁性的作用.

By using first-principle calculations, total energy and magnetic properties of transition metals （TM） doped 4H-SiC system and （A1, TM） codoped 4H-SiC system are studied. The most stable doped 4H-SiC struc- ture depends on the chemical potential of TM and Si atoms,and the most stable structure in TM doped 4H-SiC is Ti-doped 4H-SiC system. While the most stable structure in A1 and TM codoped system is （A1, V） codoped 4H-SiC. By comparing the electronic structure of the TM doped 4H-SiC and （A1,TM） codoped 4H-SiC sys- tem,A1 atom not only stabilizes the crystal structure of the 4H-SiC, but also affects the magnetic properties of the studied system.