[1] Bhilai Inst Technol Seth Balkrishan Mem, Dept Appl Phys, Near Bhilai House, Durg 491001, CG, India
[2] Pt Ravishankar Shukla Univ, Sch Studies Phys & Astrophys, Raipur 492010, CG, India
[3] Shri Shanakaracharya Vidhyalya Hudco, Dept Chem, Bhilai 490006, CG, India
[4] Govt HSC Sch, Dept Phys, Block Gunderdehi, Haldi, CG, India