Synthesis and Characterization of Superparamagnetic Fe 3 O 4 @SiO 2 Nanoparticles

Magnetite nanoparticles were prepared by co-precipitation method and then silica was coated onto the surface of Fe3O4 by hydrolysis of TEOS. The silica coated magnetite nanoparticles were characterized for its structural, microstruc- tural, optical, vibrational and magnetic properties by X-ray diffraction analysis, Scanning electron microscopy, UV-visible spectroscopy, Infrared spectroscopy and Vibration sample magnetometer, respectively. XRD study confirmed the presence of SiO2 on the surface of magnetite nanoparticles. SEM study indicated that with increase in TEOS content the particles become bigger and mono-disperse. It was also found that the silica coating prevents magnetic particles from aggregation and imparts excellent stability.