1. Electro-Materials Research Laboratory, Centre for Nanoscience and Technology, Pondicherry University, Puducherry – 605014, India
2. Department of Physics and Astronomy, College of Science, King Saud University, P. O. Box 2455, Riyadh – 11451, Saudi Arabia
3. Integrated Composites Laboratory, Department of Chemical & Biomolecular Engineering, University of Tennessee Knoxville, Knoxville, TN 37996, USA