Magnetic switching in self-organized nanoscale antidot lattices

The detailed understanding of the magnetic switching process in nanostructures is mandatory for improvements in non-volatile storage media like magnetic hard disks or magnetic random access memories. The mechanisms leading to a locally and temporally defined switching of magnetization depend on the materials involved, the size and geometry of the nanostructures and on the presence of pinning centers. The precise knowledge of the underlying processes is important for the optimization of magnetic switching for data storage applications.

The aim of project D6 is to investigate the magnetic switching in nanostructures in a wide temporal range from statics down to the picosecond time scale. Antidot lattices are used as a model system. These are prepared by self-assembly of Latex nanospheres (60-500 nm). After their homogenous size reduction by plasma etching, deposition of magnetic films, and subsequent removal of the Latex spheres including their magnetic caps we end up with a periodic antidot lattice with controllable distance and diameter of antidots. This preparation technique allows for the continuous tuning from narrow, interconnected bar-like magnets to a quasi-continuous film with small topological perturbations. The latter can be used to generate so-called magnetic vortices. The study of static and dynamic properties of such nanostructures demands the combination of state-of-the-art techniques including magnetic microscopy. The combination of experiments with complementary micromagnetic simulations leads to a comprehensive insight into magnetic antidot arrays.