1. Department of Physics, Central University of Rajasthan 1 , Ajmer 305817, India
2. Department of Physics, Hansraj College, University of Delhi 2 , Delhi 110007, India
3. Computational Electronics and Nanoscience Research Laboratory, School of Nanoscience and Biotechnology, Shivaji University 3 , Kolhapur 416 004, India
4. School of Information Technology, Halmstad University 4 , Box 823, 301 18 Halmstad, Sweden
5. Solid State Physics and NanoLund, Lund University 5 , Box 118, 221 00 Lund, Sweden