First principles investigation of pressure dependent stability, phonon, Debye temperature, physical, mechanical and thermodynamic properties of Rh3Al intermetallic compound

Pressure dependence of stability, phonon, Debye temperature, physical, mechanical and thermodynamic properties of Rh3Al intermetallic compound were investigated by first-principles The calculated cohesive energy (E-c), formation enthalpy (Delta H) show that Rh3Al is a thermodynamically stable compound. Properties related to the phonons of Rh3Al were also obtained. In addition, the transverse sound velocity (nu(s)), longitudinal sound velocity (nu(l)), average sound velocity (nu(m)) and Debye temperature (Theta(D)) of Rh3Al were calculated by using the VRH method along with pressure range from 0 to 60 GPa. The values of lattice parameters, bulk modulus and its first-order pressure derivative are consistent well with other works. The band structure indicates that Rh3Al compound exhibits a metallic character. Moreover, the total density of states, partial density of states, Mulliken charges and electron density difference have been analysed to explain the physical properties. Based on the stress-strain approach and the Born stability criteria, the mechanical properties were evaluated by elastic constants (C-ij), other modulus (B, E, G), (B/G) ratio, Poisson's ratio (nu), the anisotropic index (A), hardness (H) and compressibility (K) for this intermetallic compound. Finally, the thermodynamic properties, including enthalpy, free energy, entropy and heat capacity are discussed range from 0 to 1000 K.