1. Research Department of Physics, Namakkal Kavignar Ramalingam Government Arts College for Women, Namakkal 637001, Tamilnadu, India
2. Departmet of Research and Development Cell, Periyar University, Periyar Nagar, Salem 636011, Tamilnadu, India
3. Department of Physics, Babasaheb Bhimrao Ambedkar University, Lucknow, U. P., India
4. Department of Physics, Graphic Era (Deemed to be University), Dehradun, Uttarakhand, India