Preparation and characterization of magnetite nanoparticles with various morphologies by one method

Magnetite nanoparticles with various morphologies as sphere, cube, regular octahedron, irregular polyhedron, triangle and irregular grains have been successfully synthesized by using only one preparation method with FeSO ₄·7H₂O and NaOH as starting materials. X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) techniques were used to characterize the as-synthesized magnetite nanoparticles for their structure, shape and magnetic properties, respectively. The results show that all the assynthesized magnetite nanoparticles, are well crystallized and can be indexed into spinel structure. The saturation magnetization of octahedral magnetite nanoparticles is 86.56 emu·g^-1; the remanence magnetization and coercive forces of octahedral magnetite nanoparticles are 10.64 emu·g^-1, 138 Oe, respectively. The possible mechanism for the formation of magnetite nanoparticles with various morphologies is suggested.