1. University of Regensburg Institute of Inorganic Chemistry Universitätsstraße 31 93053 Regensburg Germany
2. University of Augsburg Institute of Physics, Chair of Solid State and Materials Science Universitätsstraße 1 86159 Augsburg Germany
3. Friedrich-Alexander-Universität Erlangen-Nürnberg Erlangen Center for Interface Research and Catalysis Egerlandstraße 3 91058 Erlangen Germany