β-CaSiO_3晶体的电子结构及光学性质  

Study on the Electronic Structure and Optical Properties of β-CaSiO_3

作　　者：何茗[1,2] 张树人[1] 周晓华[1] 李波[1] 张婷[3] 

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,成都610054 [2]成都电子机械高等专科学校电气与电子工程系,成都610031 [3]成都医学院人文信息管理学院,成都610081

出　　处：《材料导报》2011年第2期1-3,6,共4页Materials Reports

基　　金：装备预研基金重点项目(9140A12011710D20252)

摘　　要：基于第一性原理的平面波赝势方法(PWP)的局域密度近似(LDA)/广义梯度近似(GGA)计算了β-Ca-SiO3的几何结构、能带结构、态密度和光学性质。其晶胞参数优化结果与实验相比,LDA/GGA的相对误差为-3.62%/1.91%。对优化后的β-CaSiO3晶体进行能带结构分析表明,β-CaSiO3晶体为间接带隙结构,禁带宽度Eg(LDA)=5.53eV,Eg(GGA)=5.18eV。对态密度图及Mulliken电荷分布的分析表明,Ca的d轨道有电子分布,即Ca的s、p、d轨道均参与了成键。β-CaSiO3晶体中Ca与SiO3基团之间形成的化学键主要是离子键,而Si与O之间的化学键是共价键。A first-principles pseudopotential plane-wave method based on LDA/GGA method of density functional theory was used to investigate the geometry structures, band structures, density of states and optical properties of β-CaSiO3. The results show that the lattice parameter of optimization is only --3. 62%/1. 91% （relative error （RE）） within the LDA/GGA method compared with the experimental results. Based on the analysis of the band structure of optimized β-CaSiO3 crystal with LDA/GGA approximation, it is found that indirect band gaps are 5.53eV/5.18 eV. Analyses of density of states and Mulliken electron population show that there is charge distribution in the d orbit of calcium atom, which means the s, p, d orbit of calcium participate in bonding. In β-CaSiO3, the ionic bond is formed between Ca and SiOa , while the covalent bond is formed between Si and O.

关 键 词：β-CaSiO3 能带结构 电荷分布价键 

分 类 号：O484.41[理学—固体物理]