1. Center for Nanosciences, Indian Institute of Technology Kanpur, Kanpur 208016, India
2. Department of Physics, Jamia Millia Islamia, New Delhi 110025, India
3. Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, Hyderabad 500046, India
4. Defence Material and Stores Research and Development Establishment, Kanpur 208013, India