顺电相KTa_0.5Nb_0.5O₃晶体表面性质的第一性原理研究  

Properties of Paraelectric Phase KTa0.5Nb0.5O3 Surface Researched by First-Principles

作　　者：孙洪国[1] 杨小牛[1] 

机构地区：[1]中国科学院长春应用化学研究所高分子复合材料工程实验室,长春

出　　处：《现代物理》2012年第4期88-93,共6页Modern Physics

摘　　要：运用基于密度泛函理论第一性原理的局域密度近似法对具有铁电压电性能的钽铌酸钾KTa0.5Nb0.5O3晶体(100)表面进行几何结构优化,并进一步计算能带和态密度。计算得到的不同晶向表面介电函数,其它光学性质常数如反射率、折射率、传导率和能量损失函数等都可由介电函数通过计算得到。将计算结果与对应体块材料相应参数进行比较分析。结果显示表面的各种性能与体块材料存在本质的不同,与理论预期一致。Potassium tantalite niobate, KTa0.5Nb0.5O3 (KTN) has paraelectric and ferroelectric properties. The properties of crystal surfaces are studied with first-principles based on the Density Functional Theory (DFT). Geometrical struc-ture optimization, band structure, and density of states (DOS) of KTN (100) surface are calculated and analyzed. The dielectric functions of KTN (100), (110) and (111) surfaces, which can calculate all other optical properties of the mate-rial such as reflectivity, refractive index, conductivity, absorption, and energy loss function, etc. are evaluated. Compare the results with bulk, there are essential difference between interior and surface, which are according with theoretical predictions.

关 键 词：第一性原理 钽铌酸钾 表面 能带 态密度 

分 类 号：O48[理学—固体物理]