1. Institute of Inorganic Chemistry; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
2. Institute for Materials Science; Chair of Chemical Materials Synthesis; University of Stuttgart; Heisenbergstraße 3 70569 Stuttgart Germany
3. Institut Laue-Langevin; 71 avenue des Martyrs 38000 Grenoble Cedex 9 France
4. Institute of Materials Science; TU Bergakademie Freiberg; Gustav-Zeuner-Straße 5 09599 Freiberg Germany