1. Department of Physics, Government College of Engineering, Bargur, Tamil Nadu, India
2. PG & Research Department of Chemistry, Sun Arts and Science College, Tiruvannamalai, Tamil Nadu, India
3. PG & Research Department of Physics, Government Arts College, Thiruvannamalai, Tamil Nadu, India
4. Materials Science Centre, Department of Nuclear Physics, University of Madras, Chennai, Tamil Nadu, India