1. Department of Materials Science and Engineering, University of Ioannina, Ioannina 45110, Greece
2. Institute of Nanoscience and Nanotechnology, National Centre for Scientific Research-Demokritos, Athens, Greece
3. Laboratory of Materials for Electrotechnics, Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece
4. Institute of Materials Science and Computing, University Research Center of Ioannina (URCI), 45110 Ioannina, Greece