1. Materials Science Department; University of Patras; 26504 Rio Greece
2. Department of Materials Science and Engineering; University of Ioannina; 45110 Ioannina Greece
3. Regional Centre of Advanced Technologies and Materials; Department of Physical Chemistry; Faculty of Science; Palacky University in Olomouc; 17. listopadu 1192/12 771 46 Olomouc Czech Republic