1. Institute of Inorganic Chemistry Karlsruhe Institute of Technology Engesserstr. 15 76131 Karlsruhe Germany
2. Institute for Quantum Materials and Technologies (IQMT) Karlsruhe Institute of Technology Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
3. Université de Strasbourg IUT Robert Schuman CS 10315, 67411 Illkirch Cedex France
4. Univ. Bordeaux CNRS, Centre de Recherche Paul Pascal UMR 5031 33600 Pessac France
5. Institute for Nanotechnology (INT) Karlsruhe Institute of Technology Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany