1. Department of Physics, Sethu Institute of Technology, Pulloor, Kariapatti 626115, India
2. Research Centre of Physics, Fatima College, Madurai Kamaraj University, Madurai 625018, India
3. PG & Research Department of Physics, Arul Anandar College, Madurai Kamaraj University, Karumathur, Madurai 625514, India