Vapour phase approach for iron oxide nanoparticle synthesis from solid precursors

A new non-solution mediated approach to the synthesis of iron oxide nanoparticles directly from solid FeCl2 salt precursors has been developed. The method is rapid, simple and scalable. The structural properties and the phase of the resulting iron oxide particles has been determined by a range of methods including XRD, FT-IR and Mössbauer spectroscopy, and the phase is shown to be maghemite (γ-Fe2O3). The magnetic properties of the iron oxide particles have been measured using SQUID, confirming superparamagnetic behaviour of the powder and a saturation magnetization of 53.0 emu g−1 at 300 K. Aqueous dispersions at increasing concentrations were prepared and their heating rate under a 400 kHz alternating magnetic field measured. The specific absorption rate (SAR) of the iron oxide was found to be 84.8 W g−1, which makes the material suitable for the formulation of ferrofluids or ferrogels with RF heating properties.