1. Chair of Solid State and Materials Chemistry, Institute of Physics, University of Augsburg, Universitätsstraße 1, D-86159 Augsburg, Germany
2. Department of Chemistry, Faculty of Science, Paderborn University, Warburger Straße 100, D-33098 Paderborn, Germany
3. Experimental Physics V, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, Universitätsstraße 1, D-86159 Augsburg, Germany