Magnetism of Nanoclusters and Nanocluster-Assembled Thin Films

The new nanomaterials is synthesized by controlling independently the incident cluster size, concentration and nanostructures to have a wide variety of controlled optical, electronic, magnetic, mechanical and chemical properties for many technological applications. Cluster size distribution and nanocrystalline structures have been studied by TOF, AFM, SEM and HRTEM. Magnetic properties of nanoclusters and nanocluster-assembled materials have been investigated by SQUID and MFM. The dependence of magnetization is found on the cluster size and the volume fraction of Co (or Fe) clusters in Cu, SiO₂ and Fe (or Co). First-principle calculations are used to analyze the experimental data in terms of the cluster-matrix interface effects and the intercluster exchange interactions. For further understanding the nature of these cluster-assembled films, magnetic X-ray circular dichroism (MXCD) measurements have been performed. A more enhanced magnetic moment and and orbital moment will be discussed.