Optimization of magnetic property parameters of CoFe2O4/SiO2 composites prepared through coprecipitation method

Abstract

Composite of CoFe2O4 (cobalt ferrite) and SiO2 (silicon dioxide) was prepared by wet chemical route (co-precipitation). The growth of CoFe2O4 crystallite in SiO2 matrix was controlled with increasing annealing temperature (100° C to 900° C). The annealed powdered samples were characterized by X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Fourier Transform Infrared spectroscope (FTIR), and Vibrational sample magnetometer (VSM). XRD and FTIR were employed for structural analysis, phase identification, and grain size determination. The surface morphology and particle size of composite was confirmed by TEM. Response Surface methodology (RSM) was used to express the relationship between the experimental process parameters (like concentration of precursors, concentration of pH, and value of annealing temperature) and the output responses (like coercivity (Hc), remanent magnetization (Mr) and saturation magnetization (Ms)). Design Expert (version 11) was used to explore RSM and Model generated F-value for Hc, Mr and Ms were observed to be 6.86, 3.72 and 5.60, respectively. The correlation coefficient of determination R2 obtained for Hc, Mr and Ms were 0.3552, 0.0722 and 0.2197, respectively. The obtained results fitted well to model and found to be significant. XRD data of the sample heat treated at 900°C was analysed through Rietveld refinement using fullprof suite and profile parameters so obtained (Rp =17.4, Rwp=16.5 and Rexp=7.5) indicates the significance of observed pattern of XRD data.