Rapid, high-yield aqueous synthesis of ultrafine magnetite nanoparticles from Fe(III) precursor at room temperature

The magnetite Fe 3 O 4 nanoparticles have a broad range of applications due to the combination of specific magnetic and electrical properties. It is important to develop synthesis approaches where magnetite nanoparticles can be obtained from cheap precursors in large quantities rapidly. Herein, we report a straightforward process for synthesizing magnetite from Fe(III) chloride precursor. NaBH 4 -assisted precipitation of ferric chloride provides stoichiometric Fe 3 O 4 nanoparticles within 1 minute. The obtained particles exhibit superparamagnetic behavior with saturation magnetization of as high as 55.4 emu/g. The simple addition of surfactant cetrimonium bromide to the synthesis mixture allows to reduce crystallite sizes and enhance the magnetic properties even further.