Magnetic properties of Fe$_{\pmb 1}$/Cr$_{\pmb{\text{N}}}$ nanoinclusions in Fe

Abstract

The magnetic properties of Fe$_{1}$/Cr$_{N}$ inclusions in a Fe matrix are calculated as a function of the Cr number of atoms $N$ at zero temperature, and for $N \leq 168$. The electronic structure is determined by using a realistic spd-band Hamiltonian. The local magnetic moments $\mu(i)$ at the various cluster sites i are calculated selfconsistently in the unrestricted Hartree-Fock approximation. The results show clearly the importance of the local geometry and the magnetic interactions between neighbors. The matrix Fe atoms couple always antiferromagnetically to the Cr atoms, imposing for small $N$ spin arrangements that overcome the antiferromagnetic interactions of the Cr cluster. The antiferromagnetic arrangement becomes possible in the interior of the cluster as the number of Cr atoms becomes larger than 88.