Synthesis of monodispersed gamma-Fe2O3 nanoparticles using ferrocene as a novel precursor

We report synthesis of mono-dispersed nanoparticles of crystalline gamma-Fe2O3 using ferrocene as a novel precursor. Thermal decomposition of ferrocene was achieved using paraffin wax as solvent and oleic acid as surfactant. Conventionally used precursor in the thermal decomposition method is iron pentacarbonyl. The toxicity, volatility and flammability of iron pentacarbonyl are causes of concern for environment and safety. The method proposed in the present work is better in these counts. In addition, high temperature required for the decomposition of ferrocene compared to iron pentacarbonyl ensures better crystallinity of the grown nanoparticles. Also, the reaction in paraffin wax can be frozen suddenly to study the evolution of the nanoparticles. Nanoparticles, thus synthesized, were characterized using transmission electron microscopy (TEM), high resolution TEM (HRTEM) and photoelectron spectroscopy (PES). PES shows formation of iron oxide and electron diffraction reveals that the particles are crystalline and form gamma-Fe2O3 phase. TEM shows the nanoparticles are mono-dispersed in diameter (20 +/- 2 nm) and they self assemble in three-dimensional hexagonal closed packed superlattices, because of high degree of uniformity in diameter.