Influence of Al and Si concentration on the structural, electronic, magnetic, and mechanical properties of Fe2CoAl1−xSix (x = 0, 0.25, 0.5, 0.75, and 1.0) full heusler alloys: First principles calculations and Monte Carlo simulation

Abstract

A comprehensive investigation into the structural, electronic, magnetic, mechanical, and thermomagnetic properties of Fe2CoAl1−xSix (x = 0, 0.25, 0.5, 0.75, and 1.0) full Heusler alloy is performed using density functional theory and Monte Carlo simulation. Pristine and doped structures are found to adopt the XA prototype, and the lattice parameter is observed to decrease with increasing Si concentration. An increase in the bulk modulus is noticed with the increase of Si concentration, the resulted values range from 160 to 240 GPa. The electronic properties reveal a band gap in the spin-down states of the pristine and doped structures using mBJ approximation. The magnetic moments of the doped structures are found to be similar to those of the pristine structures, and the exchange interaction parameters highlight the Fe-Fe interaction as the strongest in the doped structures. The resulting Curie temperature using Monte Carlo simulation ranged between 792 K and 1029 K. Finally, understanding the magnetic properties of these Heusler alloys could pave the way for spintronics and high-temperature magnetic applications.