1. Solid State Physics Department, Physical Research Division, National Research Centre (NRC), Dokki, Giza, Egypt
2. Electronic Microscope Department, Physical Research Division, National Research Centre (NRC), Giza, Dokki, Egypt
3. Basic Science Department, Faculty of Technology and Education, Helwan University, Cairo, Egypt
4. Nanotechnology Research Center, British University in Egypt (BUE), Elshrok-city, Cairo, Egypt