1. Department of Physics, Faculty of Basic Sciences, University of Mazandaran, P.O. Box 47416-1467, Babolsar, Iran
2. Nano and Biotechnology Research Group, Faculty of Basic Sciences, University of Mazandaran, P.O. Box 47416-1467, Babolsar, Iran
3. Department of Physics, Payam-e Nour University, P.O. Box 919, Mashad, Iran
4. Department of Physics, Iran University of Science and Technology, Tehran, Iran