1. PG
and Research Department of Physics, N.M.S.S.V.N College, Madurai 625019, Tamilnadu, India
2. Department
of Physics and Nanotechnology, SRM University, Kattankulathur 603203, Tamil Nadu, India
3. UGC-DAE
Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017, India