1. Research Scholar, Manonmaniam Sundaranar University, Thirunelveli 627012, India
2. Department of Physics, St. Joseph's College of Arts and Science (Autonomous), Cuddalore, Tamilnadu 607 001, India
3. Department of Physics, Kanchi Mamunivar Center for Post Graduate Studies and Research, Lawspet, Puducherry 605 008, India
4. Research Scholar, Bharathiyar University, Coimbatore, India