Thesis (Ph.D.) - Cairo University - Faculty of Science - Department of Physics

The present study is concerned with inorganic double perovskites with the general formula La₂ FeB"O₆ , (Bʺ = Fe, Co, and Ni). In this regard the 2 6 prepared samples were classified into two groups In the first group, the double perovskite samples with the general formula of La₂ FeB"O₆ , were adjusted in a controlled way by modifying the Bʺ cations (Bʺ = Fe, Co, and Ni) through the synthesis processes. In this group, XRD, HRTEM, Raman spectra, Energy dispersive X-ray analysis (EDAX) and magnetic properties were investigated. According to results obtained from first group, the La Fe O was found to226 have the optimum values in the measured parameters. In the second group the present data summarizes the mechanism and type of core{u2013}shell nanoparticles in the hope of achieving reference for the design and enhancement of new materials to be applicable in an industrial context. In this regard the second group was divided into three sections: Section I The diphasic composites with core-shell nanostructures formed by La₂Fe₂O₆ /CoFe₂O₄ were investigated. The core-shell structure was fabricated via different preparation methods. The advantages and the demerits of the synthesis techniques were discussed. In section II: An attempt is made to study the effect of the pH variation on the preparation of La₂Fe₂O₆ /PVP core shell structure with a facile and low- cost technique

Issued also as CD