Local structure and magnetic property of Ni1−xZnxFe2O4 (x=0, 0.25, 0.50, 0.75, 1.00) nanoparticles prepared by hydrothermal method
| Autor: | Unchista Wongpratat, Ekaphan Swatsitang, Santi Meansiri |
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| Rok vydání: | 2014 |
| Předmět: |
Materials science
Extended X-ray absorption fine structure Analytical chemistry Condensed Matter Physics Atomic and Molecular Physics and Optics XANES Surfaces Coatings and Films Electronic Optical and Magnetic Materials X-ray absorption fine structure Magnetization Ferrimagnetism Ferrite (magnet) Crystallite Electrical and Electronic Engineering Fourier transform infrared spectroscopy |
| Zdroj: | Microelectronic Engineering. 126:19-26 |
| ISSN: | 0167-9317 |
| DOI: | 10.1016/j.mee.2014.04.027 |
| Popis: | This figure shows the best Fourier transform fitting of ZnFe2O4 (Zn K-edge). The fitting results indicate that Zn atom can occupy both the tetrahedral and octahedral sites, which can effect the magnetic properties.Display Omitted Ni1-xZnxFe2O4 nanoparticles were prepared by hydrothermal method in aloe vera solution.The best Fourier transform fitting indicated the site distributions of cations in spinel ferrite structure.Local structure and site distributions of cations strongly effect the magnetic properties.The replacement of Ni by Zn atoms at tetrahedral site can increase magnetization of Ni1-xZnxFe2O4. Ni1-xZnxFe2O4 nanoparticles were prepared by hydrothermal method at 220?C for 8h in aloe vera solution of pH 12. The phase structure, morphology and crystallite size were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results indicate that all samples have a cubic spinel ferrite structure and the estimated crystallite size by X-ray line broadening is in the range of 16-29nm. Cations distribution of Ni1-xZnxFe2O4 were studied by X-ray absorption fine structure (XAFS), X-ray absorption near edge structure (XANES) at Ni, Zn and Fe K-edge and extended X-ray absorption fine structure (EXAFS) at Ni and Zn K-edge. Magnetic properties were investigated by using vibrating sample magnetometer (VSM). It is found that all samples behave ferrimagnetic with the saturation magnetization (Ms) of respectively 25.64 and 17.39emu/g for NiFe2O4 and ZnFe2O4 and the Ms of Ni-Zn ferrite are increased with increasing of Zn content. The experimental and calculating results of EXAFS can be well fitted, indicating that most of Ni atoms occupy the octahedral site and some of them occupy the tetrahedral site while most of Zn atoms occupy the tetrahedral site and some of them occupy the octahedral site. In Ni-Zn ferrite, more octahedral sites can be occupied by Ni atoms as the Zn content is increased, resulting in the increasing of the saturation magnetization. |
| Databáze: | OpenAIRE |
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