1. Department of Physics, Interdepartmental Centre NIS University of Torino via P. Giuria 1 I-10125 Torino Italy
2. European Synchrotron Radiation Facility – Experiments Division 71 Avenue des Martyrs F-38000 Grenoble France
3. Forschungszentrum Juelich GmbH Peter Gruenberg Institute 7 D-52425 Juelich Germany
4. JARA-FIT RWTH Aachen University D-52056 Aachen Germany
5. Department of Applied Science and Technology Politecnico di Torino 10129 Turin Italy
6. Istituto Nazionale di Fisica Nucleare Sezione di Torino 10125 Turin Italy
7. Department of Chemistry, Interdepartmental Centre NIS and INSTM Centro di Riferimento University of Torino via P. Giuria 7 I-10125 Torino Italy
8. Instituto de Ciencia de Materiales de Madrid Consejo Superior de Investigaciones Científicas 28049 Cantoblanco Spain