Magnetic nanocomposites of nickel ferrite nanoparticles dispersed in silica matrix (NiFe2O4/SiO2) have been synthesized by coprecipitation method using metal chlorides as precursors for ferrite. Subsequently composites were annealed at 100, 200 and 300°C for 2h. Techniques employed for structural characterization of the samples, regarding phase, average crystallite/particle size, morphology and particle size distribution, were Xray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Transmission electron microscopy (TEM). NiFe2O4 particles were formed in the matrix pores and the nucleation of these particles was observed with the increase in the calcination temperature. The magnetic properties of the nanocomposites were measured by using Vibrating sample magnetometer (VSM). The particle size dependence of magnetic properties has been revealed as the coercivity and saturation magnetization of these nanocomposites were found much higher and much below the corresponding values for bulk nickel ferrite respectively. The realization of the adjustable particle sizes and the controllable magnetic properties makes the applicability of NiFe2O4 nanocomposites more versatile.
Magnetic nanocomposite, coprecipitation, nickel ferrite, silica matrix, coercivity
