1. Department of Physics, Faculty of Mathematical and Natural Sciences; University of Prishtina; Mother Theresa Str. 5 KS-10000 Prishtina Kosovo
2. Institute of Materials Science; TU Bergakademie Freiberg; Gustav-Zeuner Str. 5 D-09599 Freiberg Germany
3. Department of Physics, Faculty of Natural Sciences; University of Tirana; Boulevard Zogu I Tirana Albania