论文部分内容阅读
采用共沉淀法制备了3种不同粒径的Fe3O4纳米粒子,并分别将其分散在水中制备成磁流体。采用超导量子干涉仪分别测量了不同粒径磁粒子及其磁流体的磁性能。实验结果显示:粉末状Fe3O4粒子的比饱和磁化强度和矫顽力均随粒径的增加而增大;磁流体中的磁粒子比饱和磁化强度也随着粒径的增加而增大,但3种样品的矫顽力均为零,显示出超顺磁性;相同粒径的Fe3O4粒子,在磁流体中的比饱和磁化强度较粉末状态时为低。
Three kinds of Fe3O4 nanoparticles with different particle sizes were prepared by coprecipitation method and dispersed into water respectively to prepare magnetic fluid. The superconducting quantum interferometer was used to measure the magnetic properties of magnetic particles with different particle sizes and their magnetic fluids respectively. The experimental results show that the specific saturation magnetization and coercive force of Fe3O4 powder particles increase with the increase of particle size, and the saturation magnetization of magnetic particles in magnetic fluid also increases with the increase of particle size. However, The samples show coercivity of zero and exhibit superparamagnetism. The Fe3O4 particles with the same particle size have lower specific saturation magnetization in the magnetic fluid than the powder state.