An investigation on synthesis and magnetic properties of nanoparticles of Cobalt Ferrite coated with SiO2

Abstract

SiO₂-coated Cobalt Ferrite (CoFe₂O₄) nanoparticles were obtained by the hydrolysis of tetraethylorthosilicate in the presence of CoFe₂O₄ nanoparticles in co-precipitation. The effects of SiO₂coating on the magnetic properties of CoFe₂O₄ nanoparticles were investigated. The structural, morphological and magnetic properties of as-prepared sample were characterization by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, transmission electron microscopy (TEM), Field emission scanning electron microscopy/energy dispersive x-ray analysis (FESEM-EDAX) and magnetic measurements were investigated using vibrating sample magnetometer (VSM). The morphology analysis confirmed that the obtained composite nanoparticles consisted of CoFe₂O₄coated by SiO₂. It was shown that the saturation magnetization and coercivity of CoFe₂O₄ decreased after SiO₂ coating, which can be interpreted by the interparticle dipole-dipole interactions related to the magnetic particle volume fraction in the composite nanoparticles.