1. Department of Electrical and Electronics Engineering, Atilim University, 06836 Ankara, Turkey
2. Department of Physics, Hitit University, 19040 Corum, Turkey
3. Department of Physics, Middle East Technical University, 06800 Ankara, Turkey
4. Virtual International Scientific Research Centre, Baku State University, 1148 Baku, Azerbaijan
5. Institute of Physical Problems, Baku State University, 1148 Baku, Azerbaijan