00Mechanical, Structural, Electronic, Magnetic, and Thermomagnetic Properties of the Full-Heusler Fe 2 MnAs 1−x Si x alloy: DFT and Monte Carlo Simulation

Abstract The thermomagnetic, electronic, structural, and mechanical properties of the Fe2MnAs1 − xSix (x = 0, 0.25, 0.5, 0.75, and 1.0) full Heusler alloys were investigated using Monte Carlo simulation (MCs) and density functional theory (DFT). Both the pure and doped structures exhibit the L21 prototype, and there is a noticeable decline in the lattice parameter as the Si concentration increases. Electronic analysis was performed using Wien2k and the calculations were conducted using the full-potential linearized augmented plane wave (FP-LAPW) method implementing various approximations including GGA-PBE, mBJ-GGA, GGA + U, and PBEsol (GGAsol). Studying exchange coupling parameters revealed that ferromagnetic states primarily arise from the interactions between Fe-Mn and Fe–Fe in both pure and doped structures. The resultant Curie temperature ranged from 215 K to 490 K by investigating the magnetic properties. Additionally, different mechanical properties such as Poisson’s ratio, linear compressibility, anisotropy parameter, shear, bulk, and Young’s modulus were examined for all the structures.