A. K. Dwivedi
[
Department of Physics, Harish Chandra P.G. College, Varanasi, 221001, India
]
Sunil Kumar
[
Department of Physics, Harish Chandra P.G. College, Varanasi, 221001, India
]
M. S. Tiwari
[
Department of Physics, Dr. H.S. Gour University, Sagar, 470003, India
]