First-principles investigation on the structural properties, mechanical, anisotropy properties, electronic structure and optical properties of AlTi3N, AlTi2N, AlTi4N3 and Al2Ti3N2 nitrides

In recent years, nitrides have attracted more and more attentions. Understanding how nitrides are used in practice demands, we considered the material characteristics of the hexagonal AlTi 2 N, AlTi 4 N 3 and Al 2 Ti 3 N 2 and cubic AlTi 3 N compounds. First-principles calculations are used to examine the structural integrity, electrical characteristics, elastic anisotropy and optical characteristics of these nitrides. The findings demonstrate that the estimated parameter values and experimental data correlate rather well. The structures of these nitrides appear to be thermodynamically stable based on the calculated formation enthalpies of AlTi 3 N, AlTi 2 N, AlTi 4 N 3 and Al 2 Ti 3 N. The electric properties of these nitrides have been analyzed. The findings indicate that the materials possess metallic properties. According to elastic constants and elastic modulus results, it is found that AlTi 2 N has the more robust deformation resistance. The G/B ratio and ν values both support that AlTi 2 N and AlTi 4 N 3 are brittle materials. Through the drawn 3D contours and 2D projected Young's modulus graphs, the different anisotropy degrees of these nitrides are obtained. These nitrides have the potential to be used as materials for anti-ultraviolet coatings, according to their optical characteristics.