First-Principles Study of Structural, Electronic, Magnetic, and Thermodynamic Properties of Tetrataenite L10-FeNi Alloy

Iron–nickel alloys have received substantial interest because of their exceptional properties and diverse applications in technology and industry. In order to investigate their possible applications, the current research explored the structural, electronic, magnetic, and thermodynamic characteristics of tetrataenite L\({{1}_{0}}\)-FeNi alloy through a first-principles approach. The computations were carried out utilizing the density functional theory’s full-potential linearized augmented plane wave. For the electronic exchange-correlation function, we employed the generalized gradient approximation (GGA) and GGA+U (Hubbard potential). The computed lattice parameter and bulk moduli for tetrataenite L\({{1}_{0}}\)-FeNi exhibit excellent accord with previously reported data. The formation energy was calculated to be –0.18 eV/f.u. which confirming the structural stability of tetrataenite. The electronic structure revealed that the 3d orbitals of Ni and Fe are major elemental states that contribute to the metallic characteristics of the body-centered tetragonal (bct) L\({{1}_{0}}\)-FeNi. Meanwhile, the thermodynamic characters are investigated using the quasi-harmonic Debye mode. The thermal expansion coefficient and the heat capacities are affected simultaneously by the pressure and temperature.