[1] Bangladesh Univ Engn & Technol BUET, Dept Phys, Dhaka 1000, Bangladesh
[2] Shajalal Univ Sci & Technol, Sylhet 3100, Bangladesh
[3] Bangladesh Council Sci & Ind Res BCSIR, Ind Phys Div, BCSIR Dhaka Labs, Dhaka 1205, Bangladesh
[4] Bangladesh Atom Energy Commiss, Atom Energy Ctr Dhaka, Dhaka 1000, Bangladesh