1. Otto Schott Institute of Materials Research, Friedrich Schiller University Jena, Fraunhoferstraße 6, 07743 Jena, Germany
2. Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
3. Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Japan
4. Institute of Physics, UMR UR1-CNRS 6251, University of Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France