以氯化亚铁作为铁源,在碱性条件下通过混合溶剂热法合成了大尺寸Fe3O4八面体微晶.用X射线衍射仪(XRD),能量分散谱(EDS),扫描电子显微镜(SEM)对所得样品进行了物相,成分和形貌表征,磁性用振动样品磁强计(VSM)测试.结果显示,我们样品是纯立方相,形貌完整,高结晶度Fe3O4八面体.还发现,在混合溶液中随着乙二醇和水合肼体积比在一定范围内增大时,所得八面体尺寸也显出随之增大的趋势;样品具有跟块体接近的磁化强度Ms和相对较小的矫顽力Hc. Large scale Fe3O4 octahedral microcrystals were synthesized by mixed solvothermal method using ferrous chloride as iron source and XRD, EDS and SEM (scanning electron microscopy) The samples were characterized by their phase, composition and morphology, and their magnetic properties were measured by vibrating sample magnetometer (VSM). The results showed that our sample was pure cubic phase with complete morphology and high crystallinity of Fe3O4 octahedron. , And the volume ratio of ethylene glycol to hydrazine hydrate increased within a certain range in the mixed solution, the resulting octahedral size also showed an increasing trend; the sample has a close relationship with the bulk magnetization Ms and relatively small Coercivity Hc.