Preparation of core shell particles consisting of cobalt ferrite and silica by sol–gel process

Abstract

Core shell particles consisting of a magnetic core of cobalt ferrite (CoFe 2O 4) and a shell of silica (SiO 2) are prepared by sol–gel process using tetraethylorthosilicate (TEOS) as a precursor of silica, and metallic nitrates as precursors of ferrite. The core shell structure is confirmed by TEM. The magnetic properties of these nanocomposites are measured by PPMS in low temperature and in different Co-ferrite content. The coercivity is clearly temperature dependent and the saturation magnetization increases with the Co-ferrite content.