1. NCSR “Demokritos”, Institute of Materials Science, Agia Paraskevi 15310, Athens, Greece, Department of Materials Science, University of Patras, 26504 Rio Patras, Greece, and Foundation of Research and Technology Hellas, Institute of Chemical Engineering and High Temperature Chemical Processes, Stadiou str. Platani, P. O. Box 1414, Patras 26504, Greece