1. Institute of Materials Research; Slovak Academy of Sciences; Watsonova 47 Košice 04353 Slovak Republic
2. Department of Materials Physics; Eötvös Loránd University; Pázmány P. sétány 1/A Budapest 1117 Hungary
3. Bánki Faculty of Mechanical and Safety Engineering; Óbuda University; Népszínház utca 8 Budapest 1081 Hungary
4. Institute of Inorganic Chemistry; Slovak Academy of Sciences; Dúbravská cesta 9 Bratislava 845 36 Slovak Republic