Berlin 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 26: Thin films – coupling effects

MA 26.8: Vortrag

Mittwoch, 14. März 2018, 11:30–11:45, EB 301

Preparation and Characterization of Granular Magnetic Exchange Coupled Nano-Composites — •Runbang Shao¹, Benjamin Riedmüller¹, Balati Kuerbanjiang¹, Ulrich Herr¹, Adrian Schillik², and Berndt Koslowski² — ¹Institut für Mikro- und Nanomaterialien, Universität Ulm, Ulm, Deutschland — ²Institut für Festkörperphysik, Universität Ulm, Ulm, Deutschland

Granular magnetic exchange coupled nano-composites have potentials in further increasing the storage density of hard disk drives, and producing permanent magnets with high energy product (BH)_max. These nano-composites of nano-particles (NPs) embedded in or covered by thin films were produced, using a combination of inert gas condensation (IGC) and sputter deposition, in which variable material combinations could be selected. The sizes and volume filling factor (VFF) of the NPs could be controlled independently. SEM, especially in transmission mode (T-SEM) was used to measure the NP sizes. In case of superparamagnetic NPs, we compared these results to the magnetic particle sizes obtained by fitting the m-H curve to a superposition of Langevin functions. For blocked NPs embedded in antiferromagnetic films, a dependence of exchange bias (H_ex) and coercivity (H_c) on the ferromagnetic NP VFF was observed. We also studied the magnetisation of individual NPs by the means of MFM.