碱金属钼酸盐结构与性能关系的第一性原理研究  

First Principles Study on the Structure-Property Relationship of Alkali Metal Molybdates

作　　者：张博 王云杰 齐亚杰 丁家福 和志豪 苏欣 ZHANG Bo;WANG Yunjie;QI Yajie;DING Jiafu;HE Zhihao;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)

机构地区：[1]伊犁师范大学物理科学与技术学院,伊宁835000 [2]伊犁师范大学新疆凝聚态相变与微结构实验室,伊宁835000

出　　处：《人工晶体学报》2024年第6期999-1007,共9页Journal of Synthetic Crystals

基　　金：伊犁师范大学科研项目(22XKZZ21,2022YSZD004);新疆维吾尔自治区重点实验室开放课题(2023D04074);新疆伊犁科技计划(YZ2022Y002);新疆维吾尔自治区天山英才计划第三期(2021—2023)。

摘　　要：基于第一性原理比较研究Li_(2)MoO_(4)、Na_(2)MoO_(4)、K_(2)MoO_(4)和Rb_(2)MoO_(4)四种晶体的晶体结构、电子结构、原子布居、电荷密度分布和双折射率。研究结果表明四种晶体的带隙为直接带隙,禁带宽度相差不大,均在4.3 eV附近。随着碱金属原子半径增加,其电子轨道对能带的贡献会向高能侧靠近。键布居数和电子密度分布情况表明,Mo与O之间形成共价键,碱金属原子与O形成离子键。四种晶体中双折射率最高者为Rb_(2)MoO_(4),其在1064 nm处的双折射率为0.0225。晶体折射率数据表明碱金属原子半径与双折射率正相关。本文研究可为钼酸盐在非线性光学晶体方面的应用提供一定的参考。The crystal structures,electronic structures,atomic populations,charge density distributions and birefringence of Li_(2)MoO_(4),Na_(2)MoO_(4),K_(2)MoO_(4)and Rb_(2)MoO_(4)were compared by first principles.The results show that the bandgaps of the four crystals are direct band gaps,the differences of the bandgap between them are not large,and they are all around 4.3 eV.As the radius of alkali metal atoms increases,the contribution of their electronic orbitals to the energy bands moves closer to the high-energy side.The distribution of the bonding boule number and electron density suggests that covalent bonds are formed between Mo and O,and the alkali metal atoms form ionic bonds with O.Rb_(2)MoO_(4)has the highest birefringence of 0.0225 among the four crystals at 1064 nm.The refractive indices of the four crystals show that the radius is positively correlated with the birefringence.The study in this paper provides some references for the application of molybdate in nonlinear optical crystals.

关 键 词：碱金属钼酸盐 光学性质 双折射率 能带结构 第一性原理 密度泛函理论 

分 类 号：TB34[一般工业技术—材料科学与工程] O469[理学—凝聚态物理]