Abstract
In this article, a two-step microemulsion method to prepare nano-Fe3O4 particles was adopted. Several factors including molar ratio of water to NP-5 (R), alkali concentration, temperature, initial total iron concentration, and aging time that may affect morphology and size of the nanoparticles were discussed. It was found that such prepared nanomagnetite particles have uniform size and good morphology with R being 6.0, alkali concentration being 2.5 mol/L, temperature at 30°C and initial total iron concentration being controlled at 1.75 mol/L. The Ostwald ripening and long aging time can induce formation of cubic Fe3O4 nanocrystalline with 100–400 nm. The crystal structure of synthesized nanoparticles was found to belong to the cubic system by selected-area electron diffraction (SAED) and indexing the x-ray diffraction (XRD) pattern.
This project was supported by the National Natural Science Foundation of China (No. 20971043) and the Zhejiang Province Science Foundation (No. 2006C1118).