[1] Natl Inst Technol Warangal, Dept Phys, Warangal 506004, Telangana, India
[2] Univ West Indies, Dept Phys, Mona Campus, Kingston 7, Jamaica
[3] Lakireddy Bali Reddy Coll Engn A, Dept Elect & Instrumentat Engn, Krishna 521230, AP, India
[4] Univ Tecn Lisboa, Inst Super Tecn, Ctr Quim Estrutural DEQ, Ave RoviscoPais 1, P-1049001 Lisbon, Portugal
[5] Acharya Nagarjuna Univ, Dept Phys, Guntur 522510, AP, India