1. Department of ChemistryUniversity of Munich (LMU) Butenandtstr. 5–13 81377 München Germany
2. Institute for Mineralogy, Crystallography and Material ScienceLeipzig University Scharnhorststr. 20 04275 Leipzig Germany
3. Lumileds Phosphor Center Aachen (LPCA)Lumileds (Germany) GmbH Philipsstr. 8 52068 Aachen Germany
4. ESRF—The European Synchrotron 71 avenue des Martyrs 38000 Grenoble France