1. Department of Physics, Osnabrück University, 49076 Osnabrück, Germany
2. Institute of Chemistry of New Materials, Osnabrück University, 49076 Osnabrück, Germany
3. Faculty of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen, 47057 Duisburg, Germany
4. M. N. Mikheev Institute of Metal Physics, Ural Branch of the Russian Academy of Sciences, 620137 Yekaterinburg, Russia
5. Institute of Natural Sciences and Mathematics, Ural Federal University, 620083 Yekaterinburg, Russia
6. Helmholtz Zentrum Berlin Materialien & Energie, Albert Einstein Str 15, D-12489 Berlin, Germany
7. Institute of Experimental Physics of Functional Spin Systems, Technical University Munich, JamesFranck-Str. 1, 85748 Garching b. München, Germany