Structural, Electrical and magnetic properties of superparamagnetic TiO2 mixed ZnxMn1-xFe2O4 Nanoferrites

Abstract

XIX Abstract The objective of this thesis is to synthesize and study the structural, magnetic and electrical properties of nanoparticles made of ferrite zinc manganese using the stoichiometric formula ZnxMn1-xFe2O4 (X= 0, 0.15, 0.25, 0.35, and 0.45) respectively, were prepared using the sol-gel auto-combustion process. After combustion, the as-burnt powders were calcined at 650, 750, and 850 °C for 2 hrs to increase homogeneity and remove organic waste, where the as-burnt specimens and the specimens that calcined at 650, 750, and 850 ˚C added with a five-drop PVA as a binder to press it into circular pellets of diameter 1cm with thickness about 3 mm. The prepared pellets were sintered at 400, 600, and 800 􀔨 for 2 hrs to intensify of the specimens and, slowly allowed to be cooled naturally to examine the dielectric properties. Another purpose of this work is to blend and study the structural, magnetic and electrical properties of zinc manganese nitrate ferrite and titanium nanocomposites at 500 using the formula ZnMnFe2O4/TiO2 in different proportions (20%, 30%, 40%, 50% and 60%) respectively. prepared using the traditional ceramic method. The best results were the crystal size in this paper with a size of 15 to 38 nm with a cubic structure which was determined by XRD, while the crystal size of Mn-Znferrites/ TiO2 was from 10 to 30 nm with a cubic structure determined by X-ray diffraction (XRD) analyses. FE-SEM reveled Nano ferrites (ZnMnFe2O4) having a particle size of 25 to XX 66 nm were found. While the particle size of ZnxMn1-xFe2O4 /TiO2 the range from 37 to 72 nm. It observed the result is less than the Zn-Mn-Fe2O4 nano composite. Prominent FT- IR absorption peaks at 400 and 500 cm-1 indicated the presence of Fe-O, Mn-O, and Zn-O vibrational bands. Results from the VSM demonstrated that the magnetic nature of materials changed dramatically from pristine as magnetization rose and coercively decreased with Mn-Zn-ferrites nanoparticles. Finally, an optimal magnetic parameter value (Ms =0.80 emu/g and Hc =75 Oe) at (850) oC was obtained from the data. The dielectric properties are measured using a (LCR) meter in the frequency range of (200Hz-1MHz) at room temperature. The dielectric constant (ε'), dielectric loss angle (tanδ) and dielectric loss factor (ε'') are for Mn-Zn-Fe2O4 nanoferrites at 400, 600, and 800 􀔨 and Mn-Zn-Fe2O4/TiO2 nanocomposites in different proportions (20%, 30%, 40%, 50% and 60%) respectively are found to decrease with increasing temperatures. The prepared pellets were sintered at 500 􀔨 for 2 hrs to intensify of the specimens and slowly allowed to be cooled naturally to examine the dielectric properties.