Electronic, mechanical and thermodynamic properties of ZrC, HfC and their solid solutions studied by first-principles calculation

The electronic properties, dynamic stabilities and mechanical properties of ZrC, HfC, and their solid solutions were determined using first-principles calculations. The crystal structures and elastic moduli of Zr x Hf 1 − x C compounds were investigated under different transition metal atom solutions, and linear changes were observed in cell volumes, bond lengths and elastic properties with increasing hafnium atom content. The obtained phonon spectra and elastic constants show that all the compounds are dynamically and mechanically stable because they satisfy the corresponding stability criteria. The solid solutions of ZrC and HfC did not affect their electronic and mechanical properties. They are still metals, and their mechanical properties are comparable to those of ZrC and HfC. Moreover, the corresponding properties can be adjusted to some extent by changing the solid-solution ratio of the transition metal atoms. This provides a considerable advantage and convenience for the practical application of such materials.