Structural stability, electronic and optical properties of Zr-Al-N ternary nitrides using the first-principles explorations

Abstract

In this paper, the research focuses on the systematic discussion of the structural, electronic, phononic, and optical properties of Zr-Al-N ternary nitrides using first-principles calculations. On the basis of the enthalpy of formation as well as phonon dispersion, Zr-Al-N ternary nitrides are thermodynamically and kinetically stable, among which ZrAlN2 enjoying the best phase stability. The electronic features of these nitrides have been examined, such as their band structure, density of states, differences between electron densities, and bond population, and the results indicate that they are metallic in nature. The polycrystalline and directional static dielectric constant ε1(0) of Zr-Al-N ternary nitrides, as well as the static refractive index n(0)indicate that there are anisotropies in their optical properties. Zr2AlN has the lowest optical anisotropy in the three principal crystallographic directions of x, y and z, while Zr3AlN boasts the highest optical anisotropy in x-axis and z-axis.