摘 要： 采用微波水热法制备纳米 Fe₃O₄， 并用油酸对其进行表面改 性，获得油酸包覆的 Fe₃O₄ 纳米粒子。 利用 XRD、FT-IR、TEM 和振动 样品磁强计对 Fe₃O₄ 纳米粒子的结构、形貌、磁性能进行表征。 结果表 明：表面改性使得油酸分子中—COOH 和 Fe 离子形成化学键；改性后 的纳米 Fe₃O₄ 粒子为粒度均匀的球形，具有良好的分散性，平均粒径 约 8 nm；该产物具有超顺磁性，饱和磁化强度为 61.8 emu/g。 

关键词：微波水热法；Fe₃O₄ 纳米粒子；表面改性

Abstract: The Fe₃O₄ nano-particles were prepared by microwave hy drothermal method， and the surface of Fe₃O₄ was treated with oleic acid， so the Fe₃O₄ nano-particles coated with oleic acid was obtained. The structure， morphology and magnetism of the composite particles were characterized by X-ray diffraction(XRD)，Fourier transform infrared spec troscopy (FT-IR)， transmission electron microscope (TEM) and vibration sample magnetometer (VSM). The results showed that the chelating bidentate interaction between the—COOH group of oleic acid and the iron ions was formed， and the coated Fe₃O₄ nano-particles were uniform spherical and had good dispersion， and the average diameter were about 8 nm. The composite particles were superparamagnetism and the satura tion magnetization intensity was 61.8 emu/g. 

Keywords: microwave hydrothermal method; Fe3O4 nano-particles; sur face modification