Ni掺杂MgF_2电子结构和光学性质的第一性原理研究

Electronic structures and optical properties of Ni_xMg_(1-x)F_2 by first-principle calculations

采用基于密度泛函理论(DFT)的第一性原理平面波超软赝势方法计算了过渡金属Ni不同比例(16.67%,12.5%,8.33%,6.25%)掺杂的MgF_2晶体的几何结构、电子结构和光学性质.通过对比发现,由于Ni原子的掺入,体系的禁带宽度减小且能带中出现中间杂质带.另外,介电函数虚部以及吸收光谱图中均出现双峰结构,结合前人的计算给出了详细的物理机制.上述现象,揭示了Ni掺杂MgF_2体系在光学元器件方面的潜在应用.

The electronic structures and optical properties of the different percent （16.67%, 12.5%, 8. 33%, 6.25%） Ni-doped MgF2 are calculated from the First-principle method. The results show that the band gap decreases and there is a middle band in the gap with the substitution of Ni for Mg. The complex dielectric function and the absorption spectrum of NixMg1-xF2are also studied. The double-peak structure is found in the imaginary part of dielectric function and the absorption spectrum. All of which indicate that NixMg1-xF2 has the potential applications in optical systems.