第一性原理研究硅酸钇晶体的电子结构和物理性质

First Principle Study on the Electronic Structure and Physical Properties of Y_2SiO_5 Crystal

基于第一性原理利用CASTEP软件系统地模拟计算了理想的单斜硅酸钇晶体的电子结构、光学、力学和热力学等物理性质。光学性质的计算结果表现出了与硅酸钇结构一致的各向异性,比较得到的力学性质与实验结果基本吻合,表明硅酸钇是一种良好的韧性与耐磨性材料。运用线性响应的方法确定了声子态密度,得出其热力学性质,如等容比热、熵和德拜温度,得到的热容值与实验值符合较好。

The electronic structure, optical and mechanical properties, and thermodynamic properties of monoclinic Y2SiO5 were studied by the frist principles method. The results show that the optical properties have the obvious anisotropy. The calculated mechanical properties were in agreement with the experimental values. The calculated results indicate that the Y2SiO5 crystal possesses high resistance and toughness. The linear response method was applied to determine the phonon density of states and thermodynamic properties. The results of heat capacity were consistent with previous experiment. These could help the future theoretical research and the applications development of environmental and thermal barrier coating （ETBC） material.