1. Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247 667, India
2. Department of Physics, Faculty of Science, Jazan University, Jazan 45142, Saudi Arabia
3. Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781 039, India
4. Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee 247667, India
5. Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee 247667, India