Influence of the Local Environment on the Magnetic Properties of the Ordered Fe$\text{}_{1-x}$Al$\text{}_{x}$ Alloy

The electronic and magnetic properties of the ordered binary Fe$\text{}_{1-x}$Al$\text{}_{x}$ alloy with the B2 crystal structure were calculated for Al concentrations x=0.1875-0.5 using the supercell structure. The calculations showed that for increasing Al contents the average magnetization of Fe$\text{}_{1-x}$Al$\text{}_{x}$ falls down rapidly. Upon lowering the unit cell volume, almost all configurations of compositions with x ≥ 0.25 show the abrupt change of magnetic state from the high moment magnetic state to the low moment magnetic state with the moment reduction 0.6-0.8 μ$\text{}_{B}$ per atom. The configurations were found for which the low moment magnetic state solutions with the antiferromagnetic alignment of magnetic moments of Fe atoms at antisite positions are stable.