Temperature dependence of thermodynamic and mechanical properties of Fe2RhSi and Fe2RhGe: An ab-initio investigation

Abstract

In this research, we conducted an exploration of the thermodynamic and mechanical properties of ferromagnetic inverse Heusler alloys Fe2RhSi and Fe2RhGe employing computational methods based on pseudopotentials, plane waves, density-functional theory and density-functional Perturbation theory. Our study indicates that the alloys are dynamically stable, as evidenced by the presence of positive phonon frequencies for all modes. Moreover, our computational results of specific heat and Debye temperature exhibited a remarkable agreement with experimental measurements, confirming to the accuracy of our approach. Both alloys displayed positive thermal expansion and demonstrated a decrease in elastic constants with increasing temperature, consistent with the Born–Huang criteria for mechanical stability. These alloys also exhibit an anisotropic and ductility behavior. The ductility is attributed to their metallic bonds.