Theoretical insights into anisotropies in elastic and thermal properties of ternary β-M4AlN3 (M = V, Nb, Ta) nitrides by first-principles calculations

In this study, the first-principles calculations were employed to investigate the elastic, thermal properties, and the anisotropies in elastic modulus, Debye temperature and thermal conductivity of the ternary nitrides beta-M4AlN3 (M = V, Nb, Ta). The results showed that they are brittle and not potentially superhard materials. The anisotropy indexes, 3D surface constructions and 2D planar projections were employed to characterize the anisotropies in elastic modulus and thermal conductivity. The sequences of anisotropies in both elastic modulus and thermal conductivity are beta-V4AlN3 > beta-Nb4AlN3 > beta-Ta4AlN3. Besides, the sound velocities, Debye temperatures, and anisotropies were also discussed.

Automated summary

This study investigated the elastic, thermal properties, and anisotropies of ternary nitrides beta-M4AlN3 (M = V, Nb, Ta) using first-principles calculations, revealing that they are not potentially superhard materials. The anisotropies in elastic modulus and thermal conductivity were characterized and discussed, with beta-V4AlN3 showing the highest anisotropies followed by beta-Nb4AlN3 and beta-Ta4AlN3. Discussions also included sound velocities, Debye temperatures, and anisotropies of the materials.