Kombinierte oberflächen‐ und volumensensitive spektro‐mikroskopische XMCD‐Untersuchungen nanopartikulärer Hybridsysteme

Magnetic materials and their applications represent one of the most important research areas in modern science. Particularly, nanostructured materials arouse great interest, as they exhibit new and interesting properties, which arise from quantum mechanical effects due to their nanoscale size. For example, by utilizing contributions to the anisotropy energy induced from a high surface to volume ratio or interactions at interfaces, one can create highly specialized nanostruc-tured sample systems. Today they are already used in medical applications, like hyperthermia, or as MRI contrast agents. Possible future applications are e.g. self organized patterned nanoparticular materials in new magnetic data storage me-dia with higher storage densities. Especially magnetic nanoparticles made of iron oxide or with an iron oxide shell have attracted great attention in lifescience due to their easy dispersion in water and their biocompatibility. In the case of self-organized superlattices formed from single nanoparticles, possible applications include miniaturized components like GMR/TMR-elements. For all these dedicated applications, the magnetic as well as the non-magnetic properties have to be understood very accurately and tailored during the fabrica-tion process. This can be achieved e.g. by varying the size and the composition of the particles or by combining different materials into hybrid-nanocrystals (HNCs) or superlattices. Especially the magnetic interactions between different compo-nents or nanoparticles play a major role and, in first place, determine the proper-ties of the system. In any case suitable analyzing methods correlating the local physical and chemical-structural properties for both surface and bulk are required in order to control and properly adjust the properties of the produced samples.