1. Charles University in Prague, Department of Physics of Materials, Ke Karlovu 5, CZ-12116, Prague, Czech Republic
2. University of Žilina, Department of Materials Engineering, Žilina, Slovak Republic
3. Research Center of the University of Žilina, Žilina, Slovak Republic
4. Clausthal University of Technology, Institute of Materials Science and Technology, Clausthal-Zellerfeld, Germany