1. Nanoscience and Semiconductor Laboratories, Department of Physics, Faculty of Education; Ain Shams University; Cairo Egypt
2. Physics Department, Faculty of Education; Ain Shams University, Roxy; Cairo 11757 Egypt
3. Physics Department, Faculty of Science; Northern Border University; Arar 91431 KSA
4. Physics Department, Faculty of Science; Fayoum University; Fayoum 63514 Egypt