Bismuth substituted cobalt nano ferrites with the chemical composition Co Bi<sub>x</sub> Fe<sub>2-x</sub> O<sub>4</sub> (x = 0.00, 0.05, 0.10, 0.15, 0.20 & 0.25) were prepared b...Bismuth substituted cobalt nano ferrites with the chemical composition Co Bi<sub>x</sub> Fe<sub>2-x</sub> O<sub>4</sub> (x = 0.00, 0.05, 0.10, 0.15, 0.20 & 0.25) were prepared by sol-gel combustion method. The phase identification of prepared samples is characterised by X-ray powder diffraction (XRD) method, which confirms the formation of a single phase fcc spinal structure. The mean crystallite sizes of all prepared samples were obtained within the range of 21 (±5) nm. Transmission Electron Microscopy (TEM) images also confirmed the crystallite size of all the synthesised samples was in nano range. With the effect of Bi<sup>3+</sup> ion substitution on spinal cobalt ferrite, the magnetic properties were investigated by using Vibration Sample Magnetometer (VSM). The obtained hysteresis (M-H) curves of all the samples were analysed under the applied magnetic field of range ± 10 K Oe at 300 K. The magnetic properties such as saturation magnetisation (M<sub>s</sub>), remnant magnetization (M<sub>r</sub>) and coercivity (H<sub>c</sub>) values are tabulated, which show a decrease in trend as the bismuth ion concentration increases. This is due to the addition of Bi<sup>3+</sup> ion in the place of Fe<sup>3+</sup> ion (octahedral site) and hence the Bi<sup>3+</sup>-Fe<sup>3+</sup> ion interaction predominates as compared with the Fe<sup>2+</sup>-Fe<sup>3+</sup> ion interaction. The data obtained from magnetic studies, the variation among the magnetic properties have been investigated for all the prepared samples.展开更多
文摘Bismuth substituted cobalt nano ferrites with the chemical composition Co Bi<sub>x</sub> Fe<sub>2-x</sub> O<sub>4</sub> (x = 0.00, 0.05, 0.10, 0.15, 0.20 & 0.25) were prepared by sol-gel combustion method. The phase identification of prepared samples is characterised by X-ray powder diffraction (XRD) method, which confirms the formation of a single phase fcc spinal structure. The mean crystallite sizes of all prepared samples were obtained within the range of 21 (±5) nm. Transmission Electron Microscopy (TEM) images also confirmed the crystallite size of all the synthesised samples was in nano range. With the effect of Bi<sup>3+</sup> ion substitution on spinal cobalt ferrite, the magnetic properties were investigated by using Vibration Sample Magnetometer (VSM). The obtained hysteresis (M-H) curves of all the samples were analysed under the applied magnetic field of range ± 10 K Oe at 300 K. The magnetic properties such as saturation magnetisation (M<sub>s</sub>), remnant magnetization (M<sub>r</sub>) and coercivity (H<sub>c</sub>) values are tabulated, which show a decrease in trend as the bismuth ion concentration increases. This is due to the addition of Bi<sup>3+</sup> ion in the place of Fe<sup>3+</sup> ion (octahedral site) and hence the Bi<sup>3+</sup>-Fe<sup>3+</sup> ion interaction predominates as compared with the Fe<sup>2+</sup>-Fe<sup>3+</sup> ion interaction. The data obtained from magnetic studies, the variation among the magnetic properties have been investigated for all the prepared samples.
