水热及还原法制备单分散花生状微米磁性粒子

Fabrication of Microsized Peanut-like Magnetic Particles by Means of Hydrothermal Method and Reduction Method

以水热法制备5～8μm单分散花生状α-Fe2O3非磁性粒子,将其用H2还原得到稳定、均一的磁性粒子。XRD检测结果表明磁性粒子为体心立方结构的α-Fe。SEM照片显示粒子的花生状形貌还原前后保持一致,但磁性粒子表面呈大孔状,比表面积为23 m2/g。磁性测量显示多孔花生状α-Fe磁性粒子的矫顽力(Hc)为390 Oe、饱和磁化强度为0.22T。将其分散到硅油体系中,光学显微镜下观察到花生磁性粒子可在外磁场诱导作用下呈链状分布。

The α-Fe2O3 peanut-like particles of 5～8μm size,which are fabricated in hydrothermal method,can be reduced with H2 to stable and uniformitarian magnetic particles.The results of XRD measurement indicate that those magnetic particles are a-Fe particles with cubic structures.The SEM picture shows that those particles still remain in the previous peanut-like shape,but the particles appear in the shape of a big hole with a superficial area of 23m2 / g.The results of magnetic measurement indicate that the high coercivity （Hc） of multi-holed and peanut-like a-Fe particles is 390 Oe and their saturation magnetization （Ms） is 0.22T.Distributed in silicon oil and observed under microscope, the peanut-like particles appear in a chain-like distribution when affected by magnetic field.