Yazar "El Sayed, H. S." seçeneğine göre listele

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    AC susceptibility and hyperfine interactions of vanadium substituted barium nanohexaferrites
    (Elsevier Ltd, 2018) Almessiere, Munirah Abdullah; Slimani, Yassine; Güngüneş, Hakan; El Sayed, H. S.; Baykal, Abdulhadi
    Vanadium ions substituted BaFe12O19 nanohexaferrites, BaFe12-xVxO19 (0.0??x???0.1), were produced through the sol-gel auto-combustion route. The structure, morphology and the elemental compositions of various products were examined using X–ray powder diffraction, scanning electron microscopy coupled with EDX and EDS elemental mapping. These techniques confirmed the formation of the desired Ba-nanohexaferrite phases. The crystallites size was found to be 55–58?nm range for all products. The magnetic properties of BaFe12-xVxO19 nanohexaferrites were investigated by Mossbauer spectroscopy, ZFC-FC magnetizations and AC susceptibility. The evolutions in the values of hyperfine magnetic field, isomer shift, quadrupole splitting, and line width were deduced via Mossbauer analysis. The experiments of ZFC and FC magnetizations indicated that no blocking temperature is observed in the temperature interval 2–400?K, which signals the typical ferromagnetic (FM) behavior for the produced nanohexaferrites. A super-spin glass like behavior is noticed at lower temperatures. The experiments AC susceptibility confirmed that the strength of magnetic interactions is enhanced for lower content of V3+ (x?=?0.02). For higher amount of V3+, the magnetic interactions are weakened. The obtained results are mainly accredited to the substitutions of Fe3+ ions by V3+ ions.
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    AC susceptibility and Mossbauer study of Ce3+ ion substituted SrFe12O19 nanohexaferrites
    (Elsevier Ltd, 2018) Almessiere, Munirah Abdullah; Slimani, Yassine; Güngüneş, Hakan; El Sayed, H. S.; Baykal, Abdulhadi
    Ce3+ ion substituted SrFe12O19, SrFe12-xCexO19 (0.0???x???0.5), nanohexaferrites were fabricated by citrate sol-gel combustion approach. X–ray diffractometry (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscope (EDX), EDX Elemental mapping, Fourier transform infrared spectroscopy (FT-IR) were used to study the structure and morphology of the samples. AC magnetic susceptibility and 57Fe Mossbauer spectroscopy have been operated to examine the hyperfine structure, static and dynamic magnetic properties. The values of variations in line width, quadrupole splitting, hyperfine magnetic field, and isomer shift have been estimated. The impact of Ce-ion substitution on AC magnetic susceptibility properties of Sr-hexaferrite were explored. The AC-susceptibility measurements reveal the frequency dependence of the magnetic responses, indicating strong magnetic interactions among the nanoparticles of the various products. In addition, it is determined that the magnetic interaction between the nanoparticles is weakened in the substituted products, due to the substitution of Fe3+ ions by Ce3+ ions.
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    Magneto-optical and microstructural properties of spinel cubic copper ferrites with Li-Al co-substitution
    (Elsevier Ltd, 2018) Slimani, Yassine; Güngüneş, Hakan; Nawaz, Muhammad; Manikandan, A.; El Sayed, H. S.; Almessiere, Munirah Abdullah; Sözeri, Hüseyin; Shirsath, Sagar E.; Ercan, İsmail; Baykal, Abdulhadi
    Nanospinel Li2xCu1-xAlyFe2-yO4 ferrites with composition x?=?y?=?0.0, 0.2, 0.3 and 0.4, were successfully synthesized via hydrothermal method. The effect of co-substitution (Li and Al) on structural, morphological and magnetic properties of CuFe2O4 nanoparticles were investigated using Powder X-ray Diffraction (XRD), Fourier-Transform Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Vibrating Sample Magnetometer (VSM) and Mossbauer spectroscopic techniques. The cation distribution of all composition was calculated. Both XRD and FT-IR analyses confirmed the synthesis of single-phase spinel cubic product for all the substitutions. Mossbauer investigation showed that the Li1+ and Al3+ ions occupied B-sites. Nonetheless, some amounts of Li1+ occupy A-site. The magnetization hysteresis loops M (H), revealed that the final products with x, y?=?0.0, 0.3 and 0.4 exhibit superparamagnetic (SPM) behavior at room temperature, however the composition x, y?=?0.2 displays a ferromagnetic-like (FM) behavior. The saturation magnetization (Ms) reduces with rising the Li and Al contents. Compared to pristine CuFe2O4 spinel, the remanent magnetization (Mr), coercive field (Hc) and the magneto-crystalline anisotropy fields (Ha) improved for products synthesized with x, y?=?0.2 and then decrease for x, y?=?0.3 and 0.4. The squareness ratio Mr/Ms are less than 0.500, which suggest the single domain nanoparticles with uniaxial anisotropy for Li2xCu1–xAlyFe2-yO4 (0.0?? x, y???0.4) nanoparticles. The magneto-crystalline anisotropy constant (Keff) value is improved for Li0.8Cu0.6Al0.2Fe1.8O4 (i.e. x, y?=?0.2) magnetic nanoparticles and then decreased for higher Li and Al contents, due to the replacement of Cu and Fe ions with respectively Li and Al ions.
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    Mössbauer studies and magnetic properties of cubic CuFe2O4 nanoparticles
    (Springer New York LLC, 2019) Amir, Md.; Güngüneş, Hakan; Slimani, Yassine; Tashkandi, N. A.; El Sayed, H. S.; Aldakheel, F.; Sertkol, Murat; Sözeri, Hüseyin; Manikandan, A.; Ercan, İsmail; Baykal, Abdulhadi
    This study reports the preparation and characterization of nanocrystalline spinel powder of cubic copper ferrite nanoparticles (NPs) which have been fabricated via a cost-effective citrate sol–gel approach. The structural and morphological properties of the nanoparticles are analyzed by X-ray diffraction (XRD), Fourier transform spectroscopy (FT-IR), and scanning electron microscopy (SEM) whereas magnetic properties and Mössbauer analysis were performed using vibrating sample magnetometer (VSM) and Mössbauer spectra, respectively, and were characterized in detail. The empirical aim of this study is to perceive the transition phase of CuFe 2 O 4 as cubic symmetry which was confirmed by SEM images, and a couple of studies reported on the cubic structure of copper ferrite and discussed the magnetic properties. However, the present study gives the detailed information of the formation of cubic structure and magnetic behavior of the CuFe 2 O 4 cubic structure. X-ray diffraction measurements of resulting NPs show that the grain size of the particles is about 42.08 nm while SEM analysis showed that the particles have cubic nanostructured shapes with non-homogeneous sizes in around 80–100 nm. From 57 Fe, Mössbauer parameters consist of one superparamagnetic doublet and superposition of four sextets. VSM result shows the enhanced superparamagnetic nature of the CuFe 2 O 4 NPs. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
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    Substitution effect of Cr 3+ on hyperfine interactions, magnetic and optical properties of Sr-hexaferrites
    (Elsevier Ltd, 2018) Slimani, Yassine; Baykal, Abdulhadi; Amir, Md.; Tashkandi, N. A.; Güngüneş, Hakan; Güner, Sadık; El Sayed, H. S.; Aldakheel, F.; Saleh, Tawfik A.; Manikandan, A.
    Chromium-substituted strontium nano-hexaferrites, SrCrxFe12-xO19 (0.0?? x???1.0), were produced by the hydrothermal route. The structure, morphology, optical and magnetic properties were studied. Crystal structure, spinel phase and functional groups were verified using X-ray diffraction and Fourier Transform Infrared spectroscopy. The average crystallites size is ranging between 50 and 67?nm. Scanning electron microscopy observations indicated that the multi-grains of the particles are aggleromated and are hexagonal in shape. The isotherm plots obtained from the nitrogen physisorption experiments showed that the mesopore area and the total pore volume decreased progressively with increasing the Cr3+ content. Besides, the band gap energy (Eg) decreases from 1.75 to 1.43?eV. The magnetic hysteresis loops showed that the produced nano-hexaferrites exhibit hard ferromagnetic-like (FM) behavior. Compared to the pristine SrFe12O19 product, the deduced saturation (Ms) and remanent (Mr) magnetizations, the coercivity (Hc) and the magnetocrystalline anisotropy field (Ha) increase for lower Cr3+ content (x???0.4) and then decrease as the Cr3+ content further increases. The squareness ratio Mr/Ms are ranging between 0.5 and 0.6, suggesting the single domain nano-sized particles with uniaxial anisotropy for various synthesized products. Mossbauer analysis was done to determine the quadrupole splitting, the isomer shift, and the hyperfine magnetic field values of all products.