1. Institute of Materials and Quality Engineering, Faculty of Materials Metallurgy and Recycling, Technical University of Košice, Letná 9/A, 042 00 Košice, Slovakia
2. Department of Materials Engineering, Faculty of Mechanical Engineering, Czech Technical University in Prague, Karlovo nám. 13, 121 32 Prague 2, Czech Republic
3. Slovak Academy of Sciences, Division of Ceramic and Non-Metallic Systems, Institute of Materials Research, Watsonova 47, 040 01 Košice, Slovakia
4. Faculty of Science, Institute of Physics, Pavol Jozef Šafárik University in Košice, Park Angelinum 9, 040 01 Košice, Slovakia