Synthesis and size control of the nano-Fe₃O₄ particles synthesized by a reverse coprecipitation method

The morphology, structure and magnetic property of the nano-Fe₃O₄ particles synthesized by a reverse coprecipitation method were characterized by using transmission electron microscope (TEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The results show that nearly spherical Fe₃O₄ nanoparticles with a spinel structure were obtained which exhibited superparamagnetic behavior at room temperature. The nanoparticles was smaller and more uniform compared with those by the normal coprecipitation method.The size of the nanoparticles increased with the synthesized temperature increasing, and decreased with pH value increasing.