1. NanoMaterials Group, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076 Aalto, Espoo, Finland
2. University of Vienna, Faculty of Physics, Strudlhofgasse 4, 1090 Wien, Austria
3. LEM, UMR 104 ONERA-CNRS, 29 Avenue de la Division Leclerc, 92322 Châtillon, France
4. LMA, Instituto de Nanociencia de Aragon, U. Zaragoza, c/Mariano Esquillor, 50018 Zaragoza, Spain
5. Thule Institute, University of Oulu, P.O. Box 7300, FI-90014, University of Oulu, Finland
6. Department of Chemistry, University of Oulu, P.O. Box 3000, FI-90014, University of Oulu, Finland
7. LPS, UMR 8502 CNRS, Université Paris Sud XI, Bâtiment 510, 91405 Orsay, France
8. Department of Chemistry, Aalto University School of Chemical Technology, P.O. Box 16100, FI-00076 Aalto, Espoo, Finland