Abstract:

Airming at disadvantages for the preparation of Fe3O4 nanoparticles by chemical precipitation method including high dosage of nitrogen, a little complex preparation. Based on this method, this paper aims to prepare magnetic Fe3O4 nanoparticles in air atomosphere. The influence of molar ratio of Fe2+ and Fe3+, reactive temperature, concentration of NaOH on formation process of Fe3O4 was systematically studied. X-ray Difffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM) were used for samples characterization. The results show that Fe2+ and Fe3+ can completely reacted to obtain Fe3O4 precipation. The optimum preparation conditions are m(Fe2+)： m(Fe3+) of 1:1, temperature of 50 ℃ and NaOH concentration 0.15 mol/L. Under these conditions, the particle is complete in crystalline and sphere in shape. The particle size is smaller than 20 nm. The saturation magnetization is 3.34×105A/m, indicating strong magnetism.

Key words: Fe3O4, magnetic, oxygen, nanoparticle