1. USBAS, Guru Gobind Singh Indraprastha University Dwarka, New Delhi 110078, India
2. CSIR-Central Glass & Ceramic Research Institute, Council of Scientific & Industrial Research, Kolkata 700032, India
3. Department of Physics, Barasat Govt. College Barasat, Kolkata 700124, India
4. Surface and Nanoscience Science Division, Indira Gandhi Centre for Atomic Research, HBNI, Kalpakkam 603102, India