外磁场诱导制备麦穗形多级结构Fe_3O_4材料

Preparation of a Hierarchical Structured Wheat-ear Fe_3O_4 with Induction of an External Magnetic Field

在外磁场的诱导下,通过共沉淀法在壳聚糖溶液中成功制备了麦穗形的多级结构Fe3O4材料.扫描电子显微镜（SEM）观察发现,这种Fe3O4材料由长0.5-1.5μm、直径0.1-0.5μm的纺锤形亚微粒有序堆积而形成麦穗状;透射电子显微镜（TEM）结果表明,纺锤形亚微粒由长度为100-500nm、直径为3-7nm的Fe3O4纳米线平行排列而成.我们对这种麦穗形的多级结构Fe3O4粒子的形成进行了分析与讨论.此外,振动样品磁强计（VSM）测试结果显示,该麦穗形的多级结构Fe3O4粒子呈现超顺磁性,饱和磁化强度为18.3A·m^2/kg.

Wheat-ear Fe3O4 particles were successfully prepared in chitosan solution using co-precipitation method,where an external magnetic field was applied for induction.The micrometer-scale wheat-ear material is found to be well-organized assemblies of spindle Fe3O4 particles,which are 0.5-1.5μm in length and 0.1-0.5μm in diameter.The spindle Fe3O4 particle consists of parallel Fe3O4 nanorods,and the length and diameter of the nanorods are 100-500 nm and 3-7nm,respectively.The formation of the wheatear Fe3O4 is thought to be closely related to the external magnetic field induction.The hierarchical structured wheat-ear Fe3O4 particles display superparamagnetic properties,with a saturation magnetization of 18.3A·m^2/kg.