Abstract: Citrate ions were introduced as a complex compound in the co–precipitation method for ultrafine Fe3O4 nanoparticles preparation. Well–dispersed Fe3O4 nanoparticles were directly prepared. The principle of reaction was investigated. Dominant performance parameters of Fe3O4 nanoparticles were studied with X–ray diffraction (XRD), laser granularity scatter, atomic force microscope (AFM), transmission electron microscope (TEM), and vibration showpiece magnetor (VSM).The results showed that the as–prepared Fe3O4 nanoparticles had good dispersion and purity.The average diameter was about 30 nm, and saturation magnetization intensity was 71emu/g.

摘要： 现代诊断学的发展使得纳米级超顺磁性的Fe3O4粒子在医学领域具有重要应用价值。本实验采用分解沉淀法制备磁性纳米Fe3O4粉体。讨论了离子对Fe3O4晶粒生长的抑制机理。对获得的粉体采用激光散射法粒度测试、XRD物相分析和粒晶的计算、AFM、TEM形貌观察、振动样品磁强计等方法进行表征，结果表明，所得Fe3O4粉体平均粒径为30nm、粒度分布均匀、分布带较窄且产物纯度高；饱和磁化强度约为71 emu/g。