Synthesis and Characterization of Cobalt Ferrite Nanoparticles

Abstract

Cobalt ferrite can be synthesized using several techniques. However, to have wide applications in electronic, medical fields etc., the synthesis technique should be simple and inexpensive. The synthesis technique used to prepare nanoparticles should not consume lot of time and energy. Also it should yield narrow particle size distribution and homogeneity in the
prepared material. It was observed that surface modification such as with silica coating on the cobalt ferrite will have significant effect on the structural and magnetic properties. It is also observed that, silica coated nanoparticles could be used in biomedical applications (Hong et al., 2013). In this work we have chosen sol-gel method to synthesize pure cobalt ferrite (CoFe2O4) and silica coated (CoFe2O4 / SiO2) nanoparticles. To observe the effect of silicate coating on the structural and magnetic properties of CoFe2O4 we have carried out the present study. CoFe2O4 nanoparticles were synthesized with SiO2 coating and in pure form by sol-gel method. The obtained particle sizes were 24 and 26 nm in both the cases. The X-ray diffraction patterns showed the formation of CoFe2O4 spinel structure without any traces of SiO2 in the prepared samples. The Infrared spectra showed the bands corresponding to tetrahedral and
octahedral sites as feature of typical spinel ferrites and also band due to SiO2. The particle size and morphology of CoFe2O4 / SiO2 was found to be uniform but in the case of pure CoFe2O4 somewhat agglomerated which is accounted for magnetization of ferrites. The magnetization value for CoFe2O4 / SiO2 showed a drastic decrease when compared to pure CoFe2O4 due to presence of non-magnetic coating layer.