Synthesis and control of Fe3O4 magnetic nanoparticles

The fcc structured Fe3O4 nanoparticles are prepared using hydrolysis coprecipitation in this paper. The effect of temperature and pH on the grain size and shape of the Fe3O4 magnetic nanoparticles were discussed. The results show that, reaction temperature affects the size of Fe3O4 nanoparticles. As the temperature rising from 30 to 90°C, the grain size increases from 6-8 nm to 10-12 nm and the saturation magnetic moment also increases. Meanwhile, the shape of Fe3O4 nanoparticles varies according to the pH of the solution. High pH leads to cubic particles while low pH causes spherical shape. The controllable size and shape of Fe3O4 nanoparticles lay a good foundation for further synthesis, regulation of electro-magnetic functional Fe3O4 composites.