First-principles Calculations of the Mechanical, Electronic, and Thermodynamic Properties of Cubic Aluminum-copper Intermetallic Compounds under Pressure

Abstract

The effects of pressure on the structural stability, elasticity, electronic properties, and thermodynamic properties of Al, Al₃Cu, Al₂Cu, Al₄Cu₉, AlCu₃, and Cu were investigated using first-principles calculations. The experimental results indicate that the calculated equilibrium lattice constant, elastic constant, and elastic modulus agree with both theoretical and experimental data at 0 GPa. The Young’s modulus, bulk modulus, and shear modulus increase with increasing pressure. The influence of pressure on mechanical properties is explained from a chemical bond perspective. By employing the quasi-harmonic approximation model of phonon calculation, the temperature and pressure dependence of thermodynamic parameters in the range of 0 to 800 K and 0 to 100 GPa are determined. The findings demonstrate that the thermal capacity and coefficient of thermal expansion increase with increasing temperature and decrease with increasing pressure. This study provides fundamental data and support for experimental investigations and further theoretical research on the properties of aluminum-copper intermetallic compounds.

Keywords

intermetallics / elasticity / thermodynamic properties / ab-initio calculations

RIGHTS & PERMISSIONS

Wuhan University of Technology and Springer-Verlag GmbH Germany, Part of Springer Nature