Affiliation: | 1. Department of Physics, Dr. Ambedkar College, Nagpur 440 010, India;2. Department of Applied Physics, LIT, Nagpur University, Nagpur 440 001, India;3. Department of Applied Physics, Smt. R.P. College of Engineering, Nagpur, India;4. Department of Physics, R.K.M. College, Mylapore, Chennai, India |