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In this research, magnesium-zinc ferrite nanoparticles (Mg_1-xZn_xFe₂O₄) (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1) have been synthesized using sol-gel auto-combustion method. The X-ray diffraction analysis (XRD) revealed that the samples crystallized in a single-phase cubic spinel structure. Crystallites size of samples varies from 13nm to 29nm, also the lattice parameters and bonds length tetrahedral site (R_A) and octahedral site (R_B) of these samples have been estimated. Values of  R_A (R_B) increase (decrease) with increasing zinc content(x). The Fourier Transmission Infrared (FT-IR) spectra shows one fundamental absorption bands ν₁ in the range 1000–450 cm^-1, corresponding tetrahedral complex, respectively. The scanning electron microscope (SEM) micrographs show the uniform distribution of the particles. The saturation magnetization (Ms) and coercivity are obtained from VSM data. The saturation magnetization is found to be increased up to x = 0.4 and then decreased. These variations are attributed to the increase of magnetic moment and spin canting in the B-site.

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In this study, aluminum ion (Al³⁺) substituted yttrium iron garnet nanoparticles Y₃Al_xFe_5-xO₁₂ (x = 0.0, 0.2, 0.4) were fabricated by the sol-gel method. X-ray diffraction (XRD) patterns confirmed the pure garnet structure for all samples. The chemical bonds and the garnet phase were studied by using FT-IR, Far-FTIR. The cation distribution and the magnetic hyperfine parameters were obtained by MÖssbauer spectroscopy and confirmed the VSM results. The results of vibrating sample magnetometer (VSM) show that saturation magnetization decrease with increasing aluminum ion concentration. These changes assigned to the Neel theory and the spin canting due to the reduction of superexchange interactions between iron ions in the octahedral and tetrahedral and octahedral sites.

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In this work, Europium ion (Eu³⁺) substituted yttrium iron garnet particles Eu_xY_3-xFe₅O₁₂ (x=0.0, 1.0, 2.0) were synthesized by the sol-gel method. X-ray diffraction (XRD) patterns confirmed the pure garnet structure for all samples. The garnet phase was studied by using Far-FTIR and Raman spectroscopy. The results of vibrating sample magnetometer (VSM) represents that saturation magnetization decrease with increasing Europium ion concentration. These changes assigned to the Neel theory and spin canting after substituting Eu³⁺ in yttrium iron garnet.

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Praseodymium ion (Pr³⁺) substituted yttrium iron garnet nanoparticles Pr_xY_3-xFe₅O₁₂ (x = 0.0, 0.1, 0.2, 0.3, 0.4) were fabricated by the sol-gel method. X-ray diffraction (XRD) patterns confirmed the pure garnet structure for all samples. The chemical bonds and the garnet phase were studied by using Far-FTIR. The magnetic hyperfine parameters were obtained by MÖssbauer spectroscopy and confirmed the VSM results. The results of vibrating sample magnetometer (VSM) represents that saturation magnetization increases with increasing praseodymium ion concentration for the samples with x = 0.0 to x = 0.2 and then decreases up to x = 0.4. These changes assigned to the Neel theory, Pr³⁺ substituted at c site and the spin canting due to the sublattice splitting.

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In this work, samarium ion (Sm³⁺) substituted yttrium iron garnet nanoparticles Y_3-xSm_xFe₅O₁₂ (x=0.0, 0.2, 0.3) were fabricated by the sol-gel method. X-ray diffraction (XRD) patterns confirmed the pure garnet structure for all samples. The garnet phase were studied, using, Far-FTIR. The results of vibrating sample magnetometer (VSM) represents that saturation magnetization decrease with increasing samarium ion concentration. These changes assigned to the destrucive role of Sm⁺³  ionic size on magnetization of substituted garnet

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In this work,  Fe³⁺ substituted bismuth yttrium iron garnet particles Bi_0.5Y_2.5-xFe_5+xO₁₂ (x=0.0, 0.1, 0.2) were synthesized by the sol-gel method. X-ray diffraction (XRD) patterns confirmed the pure garnet structure for 0.0 and 0.1 samples and formation of YIP and phases in x = 0.2 sample. The results of vibrating sample magnetometer (VSM) measurements represent that saturation magnetization increases with increasing Fe³⁺cation concentration. These increases assigned to the effects of the bismuth ions in garnet structure, orientation of substituted Fe³⁺cations magnetic moments and presence of Fe²⁺cations .

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In this study, antimony substituted yttrium iron garnet with a composition of  (x = 0, 0.1, 0.2) nanoparticles were fabricated by Sol-Gel method. Garnet phase formation were investigated by X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (Far FT-IR). X-ray diffraction results show that the samples in addition to garnet phase has impurity phases of YIP, α-Fe₂O₃  and Sb₂O₄ which are appeared with incease of Sb ion substitution. The garnet phase and impurity phases was calculated using the formula klug. Percentage of the Sb ion in dodecahedral sites were calculated. Finally, Magnetic properties of nanoparticles were investigated using a vibrating sample magnetometer (VSM).The VSM pattern  show that the saturation magnetization of Sb-YIG decreases as increasing the Sb concentration.