Magnetic Moment of Binary γ-Alloys at 0 K

Abstract

A binary Ising model is applied to magnetic alloys in order to estimate the average magnetic moment per spin at 0 K by computer simulation. Two kinds of spins are assumed to distribute randomly in an FCC lattice with the coupling parameters J₁₁>0, J₁₂>0 and J₂₂<0 between nearest neighboring spins. It is shown that ferromagnetic long range order can exist if the concentration of the ferromagnetic ions exceeds a critical value which depends on the relative strengths of the couplings. In addition, the concentration dependence of the average magnetic moment is obtained and compared with experiments on Pd–Fe, Ni–Fe, Co–Fe and Ni–Mn alloys. Also discussed is the effect of the concentration-dependent atomic magnetic moment in the alloy system.