First-principle-based structural and thermodynamic parameters of Ni–Al intermetallic compounds under different pressures and temperatures

Abstract

The structural and temperature reliance manner of the thermodynamic parameters of Ni–Al intermetallic compounds with different pressures is comprehensively studied by executing first-principles calculation using the density functional theory (DFT). The calculated optimized volume and bulk modulus are in good agreement with the experimental and theoretical results at zero pressure. Quasi-harmonic Debye model is adopted to find out the bulk modulus, volumetric thermal expansion coefficient, Debye temperature, Gibbs free energy and enthalpy of Ni–Al intermetallic compounds in different pressure ranges from 0 MPa to 600 MPa and temperature ranges from 0 K to 1200 K. Additionally, special attention is paid to calculate the mutual relationships between the thermodynamic parameters with different pressures and temperatures.