Synthesis of monodispersed cubic magnetite particles through the addition of small amount of Fe3+ into Fe(OH)2 suspension

Magnetite particles were synthesized through a process including dissolution of Fe(OH)2 and precipitation of an oxidized phase in aqueous solution. The Fe3+ ion was added at the beginning of the synthesis to accelerate the formation of magnetite, control the particle size and improve the monodispersibility. It was found that the addition of Fe3+ ion affected the nucleation and the formation of magnetite particles significantly. Magnetite nanoparticles with small particle size and narrow size distribution were obtained. Furthermore, high magnetic properties were obtained in small particle size. The particle size and magnetic properties increased through the increase of Fe2+/Fe3+ ratio.