1. Institute for Clean Energy & Advanced MaterialsSchool of Materials and EnergySouthwest UniversityChongqing400715P. R. China
2. Chongqing Key Laboratory for Advanced Materials & Technologies of Clean EnergyChongqing400715P. R. China
3. College of Physics and Electronics EngineeringChongqing Normal UniversityChongqing401331P. R. China
4. Electronic & Magnetic Materials DepartmentAdvanced Materials Division, Central Metallurgical Research and Development Institute (CMRDI)HelwanP.O. Box 87Cairo11421Egypt