目的 采用一步法合成Fe3O4@C纳米粒子，分析其核壳结构的形成机理，并研究该纳米材料在磁性防伪油墨方面的应用。方法 以FeCl3•6H2O 为铁源，乙二醇为溶剂，葡萄糖为碳源，尿素为碱源，制备具有核壳结构的Fe3O4@C纳米粒子，分别采用X射线衍射、场发射扫描电镜、高分辨透射电镜、红外光谱仪和激光拉曼光谱等对其表面形貌和结构进行表征，并对所制备磁性油墨的粘度、抗摩擦性、细度和磁性进行测定。结果 所制备的Fe3O4@C纳米材料是以平均粒径18 nm的Fe3O4为核，厚度为2 nm的无定形碳为壳层的单分散球形纳米粒子，葡萄糖是核壳结构形成的关键；该材料在室温下具有典型的软磁特性, 饱和磁化强度为71.2 A•m-2/kg，矫顽力为10 984.8 A/m，所制磁性油墨的墨层耐磨性参数为81 %，印记有磁性，粘度为95 Pa•s，各项性能均符合磁性防伪油墨的要求。

The work aims to synthesize Fe3O4 nanoparticles in one-step method, analyze the processes of the formation of their core shells, and study the application of such nano-materials in magnetic anti-counterfeiting ink. Firstly, Fe3O4@C nanoparticles with a core-shell structure were synthesized. With FeCl3•6H2O as iron source, ethylene glycol as solvent, glucose as carbon source and urea as the alkali source, X-ray diffraction, field emission scanning electron microscope, high resolution transmission electron microscope, infrared spectrometer and laser Raman spectroscopy, etc. were employed to characterize the surface profile and structure of Fe3O4@C nanoparticles. Then, viscosity, friction resistance, fineness and magnetism of the prepared magnetic ink were tested. The prepared Fe3O4@C nanoparticles were the monodisperse spherical nanoparticles with Fe3O4 (mean grain size: 18 nm) as the core and 2 nm thick amorphous carbon as the shell, in which glucose played a key role in the formation of the core-shell structure. In addition, Fe3O4@C showed a typical soft magnet at room temperature with the saturation magnetization of 71.2 A•m-2/kg and coercive force of 10 984.8 A/m. For the prepared magnetic ink with magnetic mark, abrasion resistance of 81% and viscosity of 95 Pa•s, all its performances meet the requirements of magnetic anti-counterfeiting ink.