First-principles study of the structural, phonon, elastic, and thermodynamic properties of Al$_{3}$Ta compound under high pressure

TL;DR

This study uses first-principles calculations to analyze the structural, phonon, elastic, and thermodynamic properties of Al$_{3}$Ta under high pressure, revealing its stability, mechanical behavior, and thermal characteristics up to 80 GPa.

Contribution

It provides a comprehensive first-principles analysis of Al$_{3}$Ta's properties under high pressure, including phonon stability, elastic moduli, and thermodynamic behavior, which was not previously detailed.

Findings

Al$_{3}$Ta is dynamically stable up to 80 GPa.

Elastic constants satisfy mechanical stability criteria up to 80 GPa.

Higher pressure enhances hardness, ductility, and plasticity.

Abstract

We have investigated the phonon, elastic and thermodynamic properties of L1$_{2}$ phase Al$_{3}$Ta by density functional theory approach combining with quasi-harmonic approximation model. The results of phonon band structure shows that L1$_{2}$ phase Al$_{3}$Ta possesses dynamical stability in the pressure range from 0 to 80 GPa due to the absence of imaginary frequencies. The pressure dependences of the elastic constants $C_{ij}$, bulk modulus $B$, shear modulus $G$, Young's modulus $Y$, $B/G$ and Poisson's ratio $\nu$ have been analysed. The elastic constants are satisfied with mechanical stability criteria up to the external pressure of 80 GPa. The results of the elastic properties studies show that Al$_{3}$Ta compound possesses a higher hardness, improved ductility and plasticity under higher pressures. Further, we systematically investigate the thermodynamic properties, such as the Debye temperature $\Theta$, heat capacity $C_{p}$, and thermal expansion coefficient $\alpha$, and provide the relationships between thermal parameters and pressure.