1. Electronic & Magnetic Materials Department, Advanced Materials Division, Central Metallurgical Research and Development Institute (CMRDI), Helwan, P.O. Box 87, Cairo 11421, Egypt
2. State Key Laboratory of Alternate Electrical Power, System with Renewable Energy Sources, School of Renewable Energy, North China Electric Power University, Beijing 102206, China
3. Chemistry Department, Faculty of Science, Al-Azhar University, P.O. Box 11884,
Nasr city, Cairo 11421, Egypt