PUB - Publikationen an der Universität Bielefeld

Magnetic thin films and nanostructures, like nanoparticles and molecules, have unique transport properties considering their ability to eject spin polar-ised currents. In this work, the possibilities to make these properties accessi-ble by means of scanning probe microscopy have been investigated. In the first part of this thesis magnetic thin films with out-of-plane mag-netic anisotropy covered by ultrathin MgO films have been prepared and then investigated with scanning tunneling microscopy, atomic force micros-copy and magnetic force microscopy. The investigated Co/Pd and Co/Au multilayer systems showed roughness values between rms: 0.4 nm and rms: 0.8 nm. MFM images showed typical maze domain patterns. In the second part of this work magnetic molecules have been deposited on MgO covered gold substrates and entities with the size of single molecules could be isolated and AFM images have been taken. A clear phase contrast makes the entities identifiable. In the third part of this thesis the main focus lies on the measurements of the transport properties of ligand stabilized cobalt nanoparticles deposited on HOPG by means of conducting atomic force microscopy. The current-voltage curves showed gaps corresponding with the band gap of CoO/Co3O4 nanostructures.