单位：Institute of Solid State Physics, Ulm University, Germany
The magnetic properties of nanostructures have attracted huge interest within the last decade. The research is motivated by both, fundamental studies on size-dependent material properties and potential applications in data storage, senor applications, medical targeting, or hyperthermia. In my talk a short review on the tremendous development of magnetic data storage is given. The ultimate goal of storing a magnetic bit in a single magnetic entity, however, cannot be reached to date due to the superparamagnetic effect of the nanoparticles. An experimental approach is presented to circumvent thermal fluctuations at ambient temperature, i.e. the design of magnetically hard, self-assembled nanoparticles (2-10 nm).
At Ulm University we have developed combinations of chemical and physical preparation techniques aiming to self-assembled, well-ordered, and metallic nanostructures. Hardmagnetic FePt and CoPt have been prepared by reverse micelles, plasma etching and annealing and thoroughly characterized by CS-corrected high-resolution transmission electron microscopy and synchrotron-based x-ray magnetic circular dichroism.