First-principles Calculations of The Elastic Properties, Electronic Structure and Optical Properties of Hexagonal Al4SiC4

Abstract

The crystal structure, elastic constants, electronic structure and optical properties of Al4SiC4 Have been systematically investigated using the first principles calculation method based on density functional theory. The calculated lattice constants and elastic constants are consistent with the experimental and calculated values, and it shows that the hexagonal Al4SiC4 crystal structure is stable. The calculated bulk, shear, Young’s modulus and Poisson’s ratio of hexagonal Al4SiC4 are in accordance with the values in the literature. The calculated band gap of the Al4SiC4 is 1.076 eV. The changes of optical response functions of hexagonal Al4SiC4 in the (100) and (001) directions with photon energy are calculated, including complex dielectric function, complex refractive in-dex, absorption spectrum and reflection spectrum. In the (100) and (001) directions, the static dielectric con-stants are 7.74 and 8.96,respectively,and the refractive indexes are 2.78 and 2.99,respectively. The calcu-lated results can provide theoretical basis for related applications.