1. Faculty of Applied Sciences Universiti Teknologi MARA, Shah Alam 40450 Shah Alam, Selangor, Malaysia
2. Faculty of Applied Sciences Universiti Teknologi MARA, Shah Alam 40450 Shah Alam, Selangor, Malaysia;, Email: ahmad191@salam.uitm.edu.my
3. School of Applied Physics Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia