Modification of Nanosphere Templates for Nanocap and Antidot Magnetic Thin Film Fabrication

Previous work with curved magnetic thin films, such as nanocap thin films, has suggested the formation of exotic magnetic states that arise from their geometry with possible applications in biomedicine, data storage, and spintronics. This study aims to better understand the parameters, such as nanosphere diameter, nanocap shape, gap between the nanocaps, that give rise to these magnetic states by modifying polystyrene nanosphere templates via reactive ion etching (REI). Investigation into the etching of nanosphere templates by changing pressure and gas composition, as well as comparing different particle sizes, achieved a recipe for a controlled etching. Use of scanning electron microscope confirms even etching and spacing between hexagonal close packed nanosphere structures. Focused ion beam (FIB) used for cross-sectional imaging show the etched nanospheres change to spheroid shapes and sheds light on the coverage during thin film deposition. Magnetic switching property and magnetic configuration of these modified nanocap thin films will be discussed.