1. Department of Physics, Condensed Matter Research Laboratory (CMRL), Bannari Amman Institute of Technology (BIT), Sathyamangalam, Tamil Nadu, India;
2. Department of Science, Sona College of Technology, Salem, Tamil Nadu, India;
3. Department of Physics (DDE), Annamalai University, Annamalainagar, India;
4. Department of Chemistry, Bannari Amman Institute of Technology, Sathyamangalam, Tamil Nadu, India