1. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
2. Peter Gruenberg Institute (PGI-7) and JARA-FIT, Forschungszentrum Juelich GmbH, Wilhelm-Johnen-Straße, 52425 Juelich, Germany
3. Institute of Energy and Climate Research (IEK-1), Forschungszentrum Juelich GmbH, Wilhelm-Johnen-Straße, 52425 Juelich, Germany
4. Institute for Electronic Materials (IWE 2), RWTH Aachen University, Sommerfeldstraße 18/24, 52074 Aachen, Germany
5. Institute of Mineral Engineering (GHI), RWTH Aachen University, Forckenbeckstraße 33, 52074, Aachen, Germany
6. Department of Physics, University of California, Davis, California 95616, USA