[1] Womens Christian Coll, Dept Phys & Res Ctr, Nagercoil, Tamil Nadu, India
[2] Pioneer Kumaraswamy Coll, Dept Phys, Nagercoil, Tamil Nadu, India
[3] Manonmaniam Sundaranar Univ, Tirunelveli 627012, Tamil Nadu, India
[4] SRM Univ, Dept Chem, Amaravati 522240, Andhra Pradesh, India