1. Centre for Functional Materials and Nanotechnology Institute of Science Universiti Teknologi MARA Shah Alam Selangor 40450 Malaysia
2. School of Chemistry and Environment Faculty of Applied Sciences Universiti Teknologi MARA Shah Alam Selangor 40450 Malaysia
3. Faculty of Science and Marine Environment Universiti Malaysia Terengganu Kuala Nerus Terengganu 21030 Malaysia
4. Faculty of Applied Sciences Universiti Teknologi MARA Cawangan Sarawak Kota Samarahan Sarawak 94300 Malaysia
5. Physics Department Universiti Malaya Kuala Lumpur 50603 Malaysia