1. Department of Physics, Faculty of Science, University Putra Malaysia UPM, Serdang, 43400 Selangor, Malaysia
2. School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun 130022, China
3. Department of Science Laboratory Technology, Hussaini Adamu Federal Polytechnic, Kazaure, 705101 Jigawa, Nigeria
4. Institute of Advanced Materials, Universiti Putra Malaysia UPM, Serdang, 43400 Selangor, Malaysia