1. Department of Physics, Kathir College of Engineering, Coimbatore, India
2. Department of Physics, Coimbatore Institute of Technology, Coimbatore, India
3. Department of Chemistry, Bannari Amman Institute of Technology, Sathyamangalam, India
4. Department of Physics, Condensed Matter Research Laboratory (CMRL), Bannari Amman Institute of Technology, Sathyamangalam, India