Kinetics of γ-Fe2O3 nanoparticle evolution from an organic precursor

gamma-Fe2O3 particles with an average size of similar to10 nm were prepared by heating the precipitates obtained from a homogeneous solution of stearic acid and hydrated iron (III) nitrate. The compositional and thermal characteristics of the precipitates were studied with the aid of Fourier transform infrared (FT-IR) spectroscopy and differential scanning calorimetry (DSC). Presence of gamma-Fe2O3 nanoparticles in the heat treated product was established by X-ray diffraction (XRD) investigations. The average particle size was estimated from the XRD patterns by single line profile analysis and directly from transmission electron microscopic (TEM) images. Kinetic analysis of the calorimetric data revealed that nucleation and growth type kinetic law remain operative during the process and the activation energy of the process is 115 kJ/mol.