Structural and magnetic properties of Fe–Al alloys: Ab initio studies

Abstract

The structural and magnetic properties of Fe100−xAlx (5≤x≤25 at.%) alloys with different structural order are investigated within the framework of density functional theory. Using the Korringa–Kohn–Rostoker Green’s function method with a coherent potential approximation, the equilibrium lattice parameters, ground state energy and shear moduli for D03, B2 and A2 structures are calculated. For all structures, the optimized lattice constant increases and the shear modulus shows a decrease with increasing Al content. The tetragonal magnetostriction constants are estimated by the torque method. The A2 and B2 structures provide a positive contribution to the tetragonal magnetostriction. Using Monte Carlo simulations of the three-dimensional Heisenberg model, Curie temperatures are obtained over a wide concentration range.