1. European Synchrotron Radiation Facility (ESRF), BP 220, 6 Rue Jules Horowitz, 38043 Grenoble, France
2. Institut Català de Nanotecnologia (ICN), Campus UAB, 08193 Bellatera, Spain
3. Universitat Autònoma de Barcelona (UAB), Campus UAB, 08193 Bellaterra, Spain