On the oscillation of the magnetic moment of free transition metal clusters

The results of Stern–Gerlach experiments on free clusters of Fe, Co, and Ni are usually interpreted in terms of magnetic moments that show oscillations as a function of cluster size. We demonstrate that the observed behaviour can be more convincingly explained in terms of magnetic anisotropy energies (MAEs) that oscillate with the size of the clusters. The magnitudes of the estimated MAEs are in reasonably good agreement with the experimental results for supported/embedded cluster assemblies. The oscillation of the MAE of a cluster with respect to its size may reveal the geometrical shell structures of free transition metal clusters.