1. Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia , Serdang , Malaysia
2. Department of Physics, Faculty of Science, University Putra Malaysia , Serdang , Malaysia
3. Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, University Putra Malaysia , Serdang , Malaysia
4. Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia , Serdang , Malaysia