1. Department of Physics, Condensed Matter Research Laboratory (CMRL), Bannari Amman Institute of Technology, Sathyamangalam, Tamil Nadu, India;
2. Department of Chemistry, Condensed Matter Research Laboratory (CMRL), Bannari Amman Institute of Technology, Sathyamangalam, Tamil Nadu, India;
3. Department of Physics, Anna University Engineering college, Ramanathapuram, Tamil Nadu, India