Structure and Magnetism of Hybrid Fe and Co Nanoclusters up to N less than or equal to 7 Atoms

The structural and magnetic properties of small gas-phase Fe(m)Co(n) clusters with m + n ranging between 2 and 7 atoms are investigated using spin-polarized density functional theory. For a given cluster size possible compositions are subject to optimization using a variety of initial structures. The geometry, bond lengths, binding energies and magnetization are reported for the lowest energy structures. The results show that a magnetization peak occurs for Fe(4), while for hybrid clusters, switching a cobalt atom with an iron atom increases the cluster's total magnetization by 1 mu (B). Our structural predictions are generally in agreement with other theoretical results; the origin of the discrepancies arising in some cases is discussed.