Influence of the synthesis conditions on the properties of Fe ₃O₄ nanoparticles prepared by surfactant-free electrochemical method

We have been succesfully synthesized monodispersed magnetite nanoparticles by electro-oxidation of iron in plain water without using any surfactant. The characteristics of particles produced, i.e., crystallinity, size, and magnetic behavior, are influenced by the synthesis conditions including the current density and the inter-electrodes distance. The crystallinity and size of particles increase by increasing the current density and by decreasing the inter-electrodes distance. The mean size of magnetite nanoparticles produced by this method ranging from 10 to 30 nm depending on the synthesis conditions. Although there are some impurities in the form of FeOOH, which is a non-magnetic material, the nanoparticles still exhibit ferromagnetic behavior with a relatively high saturation magnetization ranging from 60 to 70emu.g_- and a coercivity ranging from 140 to 295 Oe depending on the synthesis condition. This simple method appears to be a promising synthetic route to producing magnetite nanoparticles for many applications.