1. Polymers and Pigments DepartmentChemical Industries Research Division, National Research Centre (NRC), El Bohouth St Giza Dokki Egypt
2. Inorganic Chemistry, Faculty of Science and TechnologyUniversity of Siegen Siegen Germany
3. Chemistry department, Faculty of scienceAin Shams University El‐Abaseya Egypt
4. Solid State Physics departmentPhysics Research Division, National Research Centre (NRC), El Bohouth St Giza Dokki Egypt