高压下三元层状氮化物M_(2)AlN(M=Ti,Zr)的结构、力学、电子及光学性质的第一性原理研究

First Principles Study on the Structure,Mechanics,Electronic and Optical Properties of Ternary Layered Nitride M_(2)AlN(M=Ti,Zr)under High Pressure

本文采用基于密度泛函理论的第一性原理计算方法,优化了三元层状氮化物M_(2)AlN(M=Ti,Zr)的几何结构,研究了高压下三元层状氮化物M_(2)AlN(M=Ti,Zr)的结构、力学、电子及光学性质。结构和力学性质研究表明,Ti_(2)AlN的压缩性优于Zr_(2)AlN,弹性常数证实了高压下的力学稳定性。延展性和弹性各向异性随着压力的增加而增强,Zr_(2)AlN对压力更加敏感。电子性质研究表明,两种三元层状氮化物均表现为金属性,共价性随着压力的增加而增强。Ti_(2)AlN和Zr_(2)AlN的多晶体和不同轴上的静态介电函数ε_(1)(0)以及静态折射率n(0)表明光学性质存在较低的各向异性,两种三层状氮化物都表现出较强的光吸收能力和反射率。本文的理论研究阐述了高压下三元层状氮化物Ti_(2)AlN和Zr 2AlN的相关性质,为今后的实验研究提供了比较可靠的理论依据。

This article employed a first-principles calculation method based on density functional theory to optimize the geometric structure of the ternary layered nitride M_(2)AlN(M=Ti,Zr).The structural,mechanical,electronic and optical properties of the ternary layered nitride M_(2)AlN(M=Ti,Zr)under high pressure were investigated.The study of structural and mechanical properties reveal that Ti_(2)AlN exhibits superior compressibility compared to Zr_(2)AlN.The elastic constants further validate its mechanical stability under high pressure.Ductility and elastic anisotropy enhance under increasing pressure,with Zr_(2)AlN demonstrating heightened sensitivity to these pressure conditions.Research on electronic properties reveals that both ternary layered nitrides exhibit metallic behavior,and their covalent character strengthen with increasing pressure.Investigations into the optical properties reveal that the polycrystalline nature and static dielectric functions ε_(1)(0),along with the static refractive index n(0)of Ti_(2)AlN and Zr_(2)AlN along various axes,demonstrate relatively low anisotropy in their optical characteristics.Both ternary nitrides exhibit pronounced capabilities for light absorption and reflectivity.Theoretical inquiries in this study clarified the relevant characteristics of the ternary layered nitrides Ti_(2)AlN and Zr_(2)AlN under the elevated pressure,establishing a robust theoretical framework for subsequent experimental investigations.