Magnetic and electronic properties of γ-Fe and γ-Fe/Al particles in copper

The local-density discrete variational method was employed to study the electronic structure and magnetic properties of ferromagnetic (FM) and antiferromagnetic (AFM) γ-Fe, represented by a 62-atom embedded cluster of cubic geometry, and of an iron particle in a copper matrix, represented by the cubic embedded cluster ${\mathrm{Fe}}_{14}$ ${\mathrm{Cu}}_{48}$. It was found that the Cu 3d magnetic moments are aligned parallel to the Fe 3d moments, whereas the Cu(4s,4p) moments are aligned antiparallel, in agreement with recent experiments on multilayers. The influence of substitutional Al in γ-Fe and in the Fe particle in Cu was assessed. It was found that the presence of an Al impurity disrupts the AFM state locally. Magnetic hyperfine fields were calculated in all cases for comparison with Mössbauer data.