压力及缺陷对蓝宝石电子结构影响的第一性原理研究

Study on the Electronic Structure of Sapphire Under Different Press and Vacancy Defects Using First-principles Method

基于密度泛函理论下的平面波超软赝势方法,计算了蓝宝石在三种结构相(Corundum相、Rh2O3(II)相、CaIrO3相)下的晶格参数随压力变化的关系,并得出了不同压力下的晶格常数间的比值。同时还计算了在131.2 GPa压力下不同点空位缺陷(VO+1、VO+2、VAl-1、VAl-2、VAl-3)对80个原子的超原胞AL2O3(CaIrO3相)晶体参数影响。最后为了进一步分析蓝宝石的电子结构,本文还计算了131.2 GPa压力下的AL2O3(CaIrO3相)下的理想晶体和含+2价氧空位时的总和分态密度,并将二者作了对比,结果表明+2价氧空位存在时有电子缺陷态出现。

Based on the plane-wave ultra soft pseudo method in the density-functional theory,we calculated the lattice parameters of the three perfect Al2O3 structure phases（Corundum,Rh2O3（II）,as well as CaIrO3） at 0 K under different press and get the pressure dependence of the axial rations.By comparing,we got the relationship that the lattice parameters with the press.Besides,we also calculated the different vacancy defects（VO^＋1,VO^＋2,VAl^-1,VAl^-2,VAl^-3）how effect on the lattice parameters of Al2O3 including 80 atoms under 131.2 GPa pressure.Finally,in order to analys the lattice structure we also calculated the density of states of perfect and with＋2 oxygen vacancy of Al2O3,the result indicates that＋2 oxygen vacancy arouse defect absorption.