1. Department of Physics
2. University of Ioannina
3. 451 10 Ioannina
4. Greece
5. Department of Materials Science & Nanotechnology Engineering
6. TOBB University of Economics and Technology
7. Ankara
8. Turkey
9. Institut für Chemie Neuer Materialien
10. Universität Osnabrück
11. D-49069 Osnabrück
12. Germany
13. University Research Center of Ioannina (URCI)