1. International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam-686 560, Kerala, India
2. Department of Physics, St Teresas’s College Ernakulam-682011, Kerala, India
3. School of Chemical Sciences, Mahatma Gandhi University, Kottayam-686 560, Kerala, India
4. UMR CNRS 7198, Facult́e des Sciences et Techniques, Institut Jean Lamour, Campus Victor Grignard, BP 70239, 54506, Vandoeuvre-les-Nancy Cedex, France
5. CSIR − Central Electrochemical Research Institute (CSIR-CECRI) Karaikudi-630 003, Tamil Nadu, India
6. School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam-686 560, Kerala India