Affiliation: | (1) Department of Physics, Harcourt Butler Technological Institute, Kanpur - 208 002, India;(2) Department of Physics, Harcourt Butler Technological Institute, Kanpur - 208 002, India;(3) Department of Physics, Harcourt Butler Technological Institute, Kanpur - 208 002, India;(4) Department of Physics, Harcourt Butler Technological Institute, Kanpur - 208 002, India |