الفهرس 
Nanotechnology and Nanomaterials
Synthesis of the Mn-Mg-Li nanoferrite samplesOnly 14 pages are availabe for public view
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Abstract
Recently, nanoferrites synthesis and their physical properties investigation have been under interest by many researchers due to the state-of-the-art properties exhibited by particles of the nano realm located in the transition region between atoms and bulk solids where the small size and the large specific surface area demonstrated by magnetic nanoparticles may intrinsically influence their electrical and magnetic properties. The present work aims firstly to prepare nanoparticles of Mn- Mg-Li nanoferrites by the autocombustion method with chemical compositions (Mn1-x Mgx) Li Fe O , where (x = 0.0, 0.2, 0.4, 0.5, 0.6, 0.8 and 1.0), which have not been previously investigated where it is expected that these nanoferrites are promising for multifunctional applications. Secondly, the nanocomposites of (y)(Mn1- xMgx) Li Fe O @(1-y)ZnO where (x: , and 1.0) and (y: have been synthesized by the chemical co-precipitation method. Thirdly, a comparison study of structural, elastic, magnetic, thermal, optical, and electrical properties of the as-prepared nanosamples and their nanocomposite counterparts has been conducted. Finally, the applicability of the prepared nanoferrites and their nanocomposites as photocatalysts for methyl green dye (MG dye) degradation has been investigated. The following is a concise summary of the thesis chapters: Chapter 1: Exhibits an introduction dealing with two main topics: 1. a minimalized vision of the importance of nanoferrites in modern technologies. and NC samples. The samples were investigated by BET in order to obtain their factual specific surface area and porosity. They were found to exhibit mesoporous nature. Meanwhile, their magnetic properties have been studied by using a vibrating sample magnetometer (VSM). The S-shaped of hysteresis loop (M vs. H) of all the samples reveals their soft magnetic behavior. Also, it is perceptible that the saturation magnetization Ms, experimental mexp, and theoretical magnetic moment mth values decrease while the coercivity Hc and squareness Sq increase with the increase of Mg ions content. The cation distribution of the NF samples has been suggested in which both the experimental and theoretical magnetic moments and lattice constants agree with each other. The suggested cation distribution has successfully explained the variation of the lattice parameters, crystallite size, characteristic vibration modes, magnetization, and coercivity of the samples with the substitution level. The thermal properties of the NF and NC samples, including specific heat capacity Cp, thermal conductivity Ks, and thermal diffusivity αs, have been studied due to their importance for designing various microwave devices operating at high power levels. Furthermore, the optical properties of the samples have been analyzed through UV-diffused reflectance spectroscopy (UV-DRS), where both direct and indirect band gaps have been obtained by exploiting the renowned Tauc plot. For more scrutiny of the optical properties of the investigated samples, photoluminescence (PL) has been utilized to detect the levels of defects within the bandgap and the structure of the samples. In addition, an elaborate dielectric study has been conducted to probe into the dielectric characteristics of the as-synthesized samples, such as complex permittivity, loss factor, ac and dc conductivity, complex impedance, and complex electric modulus. In this study, the effect of composition and structural parameters on the dielectric properties has been investigated. Finally, the applicability of the selected nanoferrite samples of x = , and 1.0, and the nanocomposites, in the photodegradation of the Methyl Green dye (MG), has been studied. The photocatalytic activity has been recorded for a certain concentration of the catalyst and the dye, where significant results have been obtained to promote the present Mn-Mg-Li ferrite samples along with their ZnO-based composite counterparts to be quite promising candidates as photocatalysts.