Magnetic Properties of Small, Deposited 3d Transition Metal and Alloy Clusters

Clusters are structures in the nano- or sub-nanometer regime ranging from a few atoms up to several thousand atoms per cluster. Supported metal clusters and adatoms are interesting systems for magnetic studies as their magnetic properties can strongly depend on the size, composition and the substrate due to quantum size effects. This offers rich possibilities to tailor systems to specific applications by choosing the proper size and composition of the cluster. In this article the magnetic properties of small 3d metal and alloy clusters in the few atom limit measured by X-ray magnetic circular dichroism and how their spin and orbital moments depend on size and composition are discussed. Special emphasis is put on the non-collinear magnetic coupling in the clusters resulting in complex spin structures and the influence of oxidation on the magnetic properties of the clusters.