الفهرس 
Wet Chemical Co-Precipitation Method:Only 14 pages are availabe for public view
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Abstract
This study is devoted to contribute for the best realization of the physical properties of as-synthesized and annealed FeCrxFe(2-x)O4 nano-particles (where x=0,0.2,0.4,0.6,0.8 or 1) prepared by Co-Precipitation method, La0.5Sr0.5CrxFe(1-x)O3 (where x=0,0.2,0.4,0.6,0.8 or1) prepared also by Co-Precipitation method and their composite samples. The thesis consists of five chapters: Chapter (1) represents general introduction about ferrites with their nanotechnology applications and the composite materials, also gives brief of literature review of some pervious research. Chapter (2) discloses the preparation of all samples by the wet chemical co-precipitation method, and illustrates the experimental used techniques in this study as XRD, EDX, XPS, BET, FT-IR, VSM, UV-VIS and EIS. Chapter (3,4,5) discusses the obtained results with illustrator graphs and explanatory tables of spinel ferrite system, perovskite system and their composite system respectively. Chapter (3) The study of as-prepared spinel FeCrxFe(2-x)O4 nano-particles (where x=0,0.2,0.4,0.6,0.8 or 1) prepared by co-precipitation method proved that the samples have a single phase of cubic spinel structure, while after annealed the sample at different temperatures the structure, transformed from cubic spinel to hexagonal hematite. XRD data proved that the transformation temperature decreased with increasing Cr concentration, also the crystalline size, elastic properties increased with Cr concentration and annealed temperature. VSM hysteresis loops revealed that the samples are soft ferrimagnetic materials. The saturation and remnant magnetization, squareness, magnetic moment, anisotropy constant and coercivity were affected by the Cr concentration and annealed temperature. XPS of the samples showed two peaks around 710 and 723eV attributed to Fe 2P3/2 and Fe 2P1/2, while they showed another two peaks around 575eV and 587eV attribute to Cr 2P3/2 and Cr 2P1/2 where the fitting of XPS spectra proved that the distribution of of Fe2+ and Fe3+ ions in A- and B-sites and Cr metallic, Cr2O3, Cr3+ and Cr6+ ions in B-site were affected by the Cr concentration and the sintered temperature. The energy band gap increased with Cr concentration and sintered temperature. Chapter (4) The study of perovskite La0.5Sr0.5CrxFe(1-x)O3 (where x=0,0.2,0.4,0.6,0.8 or1) prepared by co-precipitation method proved that the samples have a orthorhombic perovskite structure in nano-metric scale. The XRD data proved that the crystallite size, porosity, strain and Debye temperature were decreased with increasing the Cr concentration, whereas the lattice constant, density and specific surface area were increased. VSM hysteresis loop revealed that the samples are hard ferrimagnetic materials. The saturation magnetization MS of the samples was decreased with increasing the Cr concentration. The energy band gap increased with Cr concentration. Chapter (5) The study of the composite samples between perovskite phase and ferrite phase effects on the physical properties. The saturation magnetization MS of the as-prepared and sintered samples was increased with increasing the spinel concentration and was transferred from soft magnetic material to hard magnetic material, the saturation magnetization of the annealed composite samples increased with increasing the sintered temperature and the sintering time. The energy band gap of composite samples was increased very slowly with all factors.