Abstract Fe3O4 magnetic nanoparticles were prepared by the aqueous co-precipitation of FeCl3·6H2O and
FeC12·4H2O with addition of ammonium hydroxide. The conditions for the preparation of Fe3O4 magnetic nanoparticles
were optimized, and Fe3O4 magnetic nanoparticles obtained were characterized systematically by means of
transmission electron microscope (TEM), dynamic laser scattering analyzer (DLS) and X-ray diffraction (XRD).
The results revealed that the magnetic nanoparticles were cubic shaped and dispersive, with narrow size distribution
and average diameter of 11.4 nm. It was found that the homogeneous variation of pH value in the solution via the
control on the dropping rate of aqueous ammonia played a critical role in size distribution. The magnetic response
of the product in the magnetic field was also analyzed and evaluated carefully. A 32.6 mT magnetic field which is
produced by four ferromagnets was found to be sufficient to excite the dipole moments of 0.05 g Fe3O4 powder 2
cm far away from the ferromagnets. In conclusion, the Fe3O4 magnetic nanoparticles with excellent properties were
competent for the magnetic carriers of targeted-drug in future application.
Keywords targeted-drug, Fe3O4, magnetic particle, nanometre