1. Centre for X-ray and Nano Science, Deutsches Elektronen-Synchrotron (DESY), Germany
2. Institute of Physical Chemistry, Universität Hamburg, Germany
3. Helmholtz Zentrum Hereon, Germany
4. Institute of Advanced Ceramics, Hamburg University of Technology, Germany
5. Department of Mechanical Engineering, Eindhoven University of Technology, Netherlands
6. ams-OSRAM International GmbH, ams OSRAM Group, Leibnizstr. 4, 93055 Regensburg, Germany
7. Fraunhofer Center for Applied Nanotechnology, Grindelallee 117, 20146 Hamburg, Germany
8. Physics Department, Universität Hamburg, Germany