1. Department of Physics, Faculty of Science Universiti Putra Malaysia Serdang 43400 Malaysia
2. Department of Physics Federal University of Kashere P. M. B. 0182 Gombe, Gombe State Nigeria
3. Introp Universiti Putra Malaysia Serdang 43400 Malaysia
4. Department of Chemistry, Faculty of Science Universiti Putra Malaysia Serdang 43400 Malaysia