1. Department of Chemistry and INSTM Research Unit University of Pavia Via Taramelli 12 27100 Pavia Italy
2. Institute of Nanoscience and Nanotechnology National Center for Scientific Research “Demokritos” Patr. Grigoriou E' & 27 Neapoleos str. 15341 Agia Paraskevi Greece
3. Department of Physics University of Pavia Via Bassi 6 27100 Pavia Italy