摘要
本文基于第一性原理方法对比研究了钨酸盐TMWO4(TM=Zn、Cd、Hg)的电子结构和光学性质。研究结果表明,ZnWO_(4)、CdWO_(4)和HgWO_(4)三种钨酸盐的带隙均为直接带隙,带隙宽度分别为2.579、2.081和2.538 eV。三种钨酸盐价带顶部主要由O-2p态贡献,由于杂化效应,O-2p态和W-5d态共同组成导带底部。键布居数和电子局域函数表明,存在两种W-O键,W-O1长键为离子键,W-O2短键为共价键,金属阳离子(Zn、Cd、Hg)与O原子形成离子键。同种钨酸盐在不同方向上的介电函数都表现出差异,较大的Δε对双折射率Δn有积极的影响。随着d10电子构型金属阳离子的半径增大,钨酸盐的双折射率减小,在1 064 nm处ZnWO_(4)、CdWO_(4)和HgWO_(4)的双折射率分别为0.192、0.187和0.078,其中ZnWO_(4)和CdWO_(4)的双折射率和各向异性在三种体系中较大。
This study is based on the first-principles method to comparatively study the electronic structure and optical properties of tungstate TMWO_(4)(TM=Zn,Cd,Hg).The research results show that ZnWO_(4),CdWO_(4) and HgWO_(4) are all direct band gap materials,and the band gap widths are 2.579,2.081 and 2.538 eV.The top of the valence band of the three compounds is mainly contributed by the O-2p state.Due to the hybridization effect,the O-2p state and the W-5d state form the bottom of the conduction band together.Analysis of the bond population and electron localization function shows that,there are two kinds of W-O bonds,of which the W-O1 long bond is ionic bond,and the W-O2 short bond is covalent bond;the metal cations form ionic bonds with O atoms.Each type of tungstate exhibits differences in dielectric functions at different directions.A larger Δε has a positive impact on the birefringenceΔn.As the radius of the metal cation with d^(10) electronic configuration increases,the birefringence of the crystal decreases.The birefringence of ZnWO_(4),CdWO_(4) and HgWO_(4) are 0.192,0.187 and 0.078 at 1064 nm.Among the three systems,ZnWO_(4) and CdWO_(4) show larger birefringence and anisotropy.
作者
崔健
和志豪
丁家福
王云杰
万俯宏
李佳郡
苏欣
CUI Jian;HE Zhihao;DING Jiafu;WANG Yunjie;WAN Fuhong;LI Jiajun;SU Xin(School of Physical Science and Technology,Yili Normal University,Yining 835000,China;Xinjiang Laboratory of Phase Transitions and Microstructures of Condensed Matter Physics,Yili Normal University,Yining 835000,China)
出处
《人工晶体学报》
北大核心
2025年第5期841-849,共9页
Journal of Synthetic Crystals
基金
新疆维吾尔自治区重点实验室开放课题(2023D04074)
伊犁师范大学科研项目(22XKZZ21)
伊犁师范大学大学生创新训练项目(S202210764014,S202210764016,S202210764015)。
关键词
钨酸盐
第一性原理
电子结构
光学性质
双折射率
tungstate
first-principle
electronic structure
optical property
birefringence
