1. Institute for Nuclear Waste Disposal (INE), Karlsruhe Institute of Technology, P.O. 3640, D-76021 Karlsruhe, Germany
2. Institute for Inorganic Chemistry, Karlsruhe Institute of Technology, P.O. 3640, D-76021 Karlsruhe, Germany
3. Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, P.O.
3640, D-76021 Karlsruhe, Germany
4. ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France
5. Institute for Theoretical Physics, University of Heidelberg, Philosophenweg 19, D-69120 Heidelberg, Germany
6. Institute of Nanotechnology (INT), Karlsruhe Institute of Technology, P.O. 3640, D-76021 Karlsruhe, Germany