1. Department of Physics, Faculty of Science and Arts, Ahi Evran University, Asikpasa Kampusu, 40040 Kirsehir, Turkey
2. Department of Physics, Faculty of Science and Arts, Firat University, 23169 Elazig, Turkey
3. Department of Physics, Faculty of Science and Arts, University of Gazi, Teknikokular, 06500 Ankara, Turkey
4. CNR-IMEM Institute, Area delle Science 37/A, 43010 Fontanini, Parma, Italy