1. Functional Nano-Materials (FuN) Laboratory, Department of Physics and Nanotechnology, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu 603203, India
2. Department of Medical Physics, Anna University, Chennai, Tamil Nadu 600025, India
3. National Centre for Nanoscience and Nanotechnology, University of Madras, Chennai, Tamil Nadu 600025, India