1. Solid State Research Laboratory, Department of Physics, Burdwan University, Burdwan 713104, West Bengal, India
2. Institut des Molécules et Matériaux du Mans-IMMM UMR CNRS 6283, Le Mans Université, 72085 Le Mans Cedex 9, France
3. Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India