[1] Department of Physics, Kuvempu University, Shankaraghatta, 577 451, Karnataka
[2] Department of Engineering Physics, K.L.E. Institute of Technology, Hubballi, 580 027, Karnataka
[3] X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, Penang
[4] Department of Physics, Government First Grade College, Kumta, 581 343, Karnataka