(Th,Pa)O_(2)和(U,Pa)O_(2)的结构与性质的密度泛函研究  

Structure and properties of(Th,Pa)O_(2)and(U,Pa)O_(2) compound from density functional studies

作　　者：刘涛 杨子义 于晓燕 陈雨青 高涛[2] LIU Tao;YANG Zi-Yi;YU Xiao-Yan;CHEN Yu-Qing;GAO Tao(School of Electronic and Communication Engineering,Guiyang University,Guiyang 550005,China;Institute of Atomic and Molecular Physics,Sichuan University,Chengdu 610065,China)

机构地区：[1]贵阳学院电子与通信工程学院,贵阳550005 [2]四川大学原子与分子物理研究所,成都610065

出　　处：《四川大学学报（自然科学版）》2022年第6期113-120,共8页Journal of Sichuan University(Natural Science Edition)

基　　金：贵阳学院博士科研启动项目(GYU-KY-(2022))。

摘　　要：本文基于密度泛函理论的第一性原理,采用广义梯度近似的PBEsol+U方法计算了ThO_(2)、PaO_(2)、UO_(2)、(Th,Pa)O_(2)和(U,Pa)O_(2)的结构、力学、电子和光学性质.结构优化的结果表明PBEsol+U方法能对锕系氧化物ThO_(2)、PaO_(2)和UO_(2)提供较好的晶格参数和力学参量.计算ThO_(2)、PaO_(2)和UO_(2)的晶格参数和带隙与实验值和相关理论值做了比较,且与实验值吻合较好.同时,(Th,Pa)O_(2)和(U,Pa)O_(2)的晶格参数处于ThO_(2)与UO_(2)之间,同时预测(Th,Pa)O_(2)和(U,Pa)O_(2)的带隙也处于ThO_(2)与UO_(2)的带隙值之间.电子性质计算表明PaO_(2)和UO_(2)是Mott绝缘体,而ThO_(2)是电荷转移绝缘体,这些是和实验和理论结论是一致的.而(Th,Pa)O_(2)和(U,Pa)O_(2)在费米能级附近的电子态有显著的自旋极化效应,且导带分别主要是Pa-5f和U-5f电子态占据.最后,对比分析了这些体系的光学介电函数的实部和虚部以及光学参数.Based on the first-principles of density functional theory,we use the PBEsol+U method to calculate the lattice and electronic structures,as well as mechanical and optical properties of ThO_(2),PaO_(2)and UO_(2)and(Th,Pa)O_(2)and(U,Pa)O_(2).The results of structural optimization indicate that the PBEsol+U method can provide more accurate lattice and mechanical parameters for actinide-based oxide ThO_(2),PaO_(2),and UO_(2).The calculation results show that the lattice parameters and the bandgaps of ThO_(2),PaO_(2),and UO_(2)are consistent with the experimental values and other related theoretical values.In the meanwhile,the lattice parameters of(Th,Pa)O_(2)and(U,Pa)O_(2)are between ThO_(2)and UO_(2),while predicting the band gaps of(Th,Pa)O_(2)and(U,Pa)O_(2)are also between ThO_(2)and UO_(2).Electronic properties calculations indicate that PaO_(2)and UO_(2)are Mott insulators,while ThO_(2)is a charge-transfer insulator.These are consistent with experiments and theoretical conclusions.(Th,Pa)O_(2)and(U,Pa)O_(2)have significant spin polarization effects near the Fermi energy level,and the bands are mainly occupied by Pa-5f and U-5f electronic state,respectively.Lastly,the real and imaginary parts and optical parameters of the optical dielectric functions of these systems are compared and analyzed.

关 键 词：(Th Pa)O_(2) (U Pa)O_(2) 结构 电子性质 密度泛函理论 

分 类 号：O469[理学—凝聚态物理]