1. Department of Interface ScienceFritz Haber Institute of the Max Planck Society 14195 Berlin Germany
2. Department of PhysicsRuhr-University Bochum 44780 Bochum Germany
3. Rossendorf Beamline at ESRF—The European SynchrotronCS40220 38043 Grenoble Cedex 9 France
4. Helmholtz Zentrum Dresden-Rossendorf (HZDR)Institute of Resource Ecology PO Box 510119 01314 Dresden Germany