Nb^(5+)掺杂钛酸锶结构与性能的第一性原理研究  

First principles study of structure and property of Nb^(5+)-doped SrTiO_(3)

作　　者：龚凌云 张萍 陈倩 楼志豪 许杰[1] 高峰[1] Gong Ling-Yun;Zhang Ping;Chen qian;Lou Zhi-Hao;Xu Jie;Gao Feng(State Key Laboratory of Solidification Processing,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi'an 710072,China;School of Chemistry and Chemical Engineering,Northwestern Polytechnical University,Xi'an 710072,China)

机构地区：[1]西北工业大学材料学院,凝固技术国家重点实验室,西安710072 [2]西北工业大学化学与化工学院,西安710072

出　　处：《物理学报》2021年第22期260-269,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51672219);陕西省重点研发计划国际合作项目(2020KW-032)资助的课题.

摘　　要：本文选取SrTiO_(3)材料进行B位Nb^(5+)离子掺杂改性,采用第一性原理计算了不同含量(0%,12.5%和25%)Nb^(5+)掺杂SrTiO_(3)的电子结构、光学、力学和热学性质.结果表明,当Nb^(5+)掺杂浓度上升,材料晶胞参数增大;Nb^(5+)掺杂后SrTiO_(3)由间接带隙化合物转变为直接带隙化合物,Nb^(5+)掺杂使材料反射系数、吸收系数、能量损耗下降、脆性降低,当Nb^(5+)掺杂浓度上升,材料体弹性模量不变,剪切模量与杨氏模量减小,泊松比增大,德拜温度降低,晶格热导率与理论最低晶格热导率减小.The modification of SrTiO_(3) materials by doping Nb^(5+) ions in B-site is studied through using the first-principles method to calculate the electronic structure,optical properties,mechanical properties and thermal properties at different Nb^(5+) doping concentrations.The calculation results show that as the doping content of Nb^(5+) increases,the lattice parameters increase.After being doped with Nb^(5+),SrTiO_(3) changes from an indirect band gap compound into a direct band gap compound.Doping Nb^(5+)can reduce the reflection coefficient,absorption coefficient,and energy loss of SrTiO_(3) material,which can be used to modify its optical properties.Additionally,the brittleness of SrTiO_(3) material is improved through doping Nb^(5+).As the doping content of Nb^(5+) increases,the elastic modulus of the material hardly changes,the shear modulus and Young's modulus decrease,the Poisson's ratio increases,and the Debye temperature decreases,and both the lattice thermal conductivity and the theoretical minimum lattice thermal conductivity decrease as well.

关 键 词：Nb^(5+)掺杂SrTiO_(3) 第一性原理 光学性能 热学性能 

分 类 号：O469[理学—凝聚态物理] TQ132.33[理学—电子物理学]