1. ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, FR-38043 Grenoble Cedex 9, France
2. Department of Physics and Astronomy, University of Turku, FI-20014 Turun Yliopisto, Finland
3. Fakultät Physik/DELTA, Technische Universität Dortmund, D-44221 Dortmund, Germany
4. Nanoparticle Process Technology, University of Duisburg-Essen, D-47057 Duisburg, Germany
5. Institute of Geology and Mineralogy, University of Cologne, D-50674 Köln, Germany