1. Materials Engineering Research Group, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
2. Centre of Research in Energy and Advanced Materials, Faculty of Engineering, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
3. Department of Materials, Kyushu University, Fukuoka, Japan
4. Department of Mineral Resources and Energy Engineering, Jeonbuk National University, Deokjin-gu, South Korea
5. Surface Analysis and Materials Engineering Research Group, School of Mathematics, Statistics, Chemistry and Physics, College of Science, Technology, Engineering and Mathematics, Murdoch University, Perth, Australia