[1] Vinayaka Mission Res Fdn, Sch Arts & Sci, Dept Phys, AV Campus, Chennai, Tamil Nadu, India
[2] Vel Tech Rangaarajan Dr Sagunthala R&D Inst Sci &, Dept Phys, Sch Sci & Humanities, Chennai 600117, Tamil Nadu, India
[3] Mahendra Arts & Sci Coll, Dept Phys, Namakkal, India
[4] Hindustan Inst Technol & Sci, Dept Phys, Chennai, Tamil Nadu, India
[5] Anna Univ, Ctr Nanosci & Nanotechnol, Chennai, Tamil Nadu, India