单分散Fe3O4亚微米球的粒径控制合成及表征

Size-controlled Synthesis and Characterization of Monodisperse Fe3O4 Submicrospheres

摘要:

采用溶剂热还原法，以FeCl3?6H2O和乙二醇为原料，在200℃相对低温条件下成功合成四氧化三铁微米球。通过改变实验条件，可在115～435 nm范围内有效调控Fe3O4亚微米球的粒径。采用X射线衍射仪(XRD)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)对样品的结构、粒径、形貌和组成进行了分析，并在室温下测试了它的磁学性能。结果表明：产物Fe3O4亚微米球为反尖晶石结构, 330 nmFe3O4亚微米球的矫顽力(Hc)为83.5 Oe, 饱和磁化强度(Ms)为81.2 emu/g, 剩余磁化强度(Mr)为14.6 emu/g.。研究了乙二醇和NaOH的浓度、反应时间对产物形貌的影响, 结果表明乙二醇在Fe3O4亚微米球的形成过程中起着关键作用, 并提出了可能的生长机理。

Abstract:

Fe3O4 submicrospheres were synthesized by the solvothermal synthesis at 200℃, using FeCl3?6H2O and ethylene glycol as reactants. The size of as-prepared Fe3O4 submicrospheres could be controlled in the range of 115-435nm in diameter by adjusting some growth parameters. The structure, size, morphology and composition of the as-prepared Fe3O4 submicrospheres were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM). The results showed that the Fe3O4 submicrospheres were of inverse spinel structure. Magnetic propertie of 330 nm Fe3O4 submicrospheres has been detected by a vibrating sample magnetometer at room temperature. The coercive force, saturation magnetization and remanent magnetization of 330nm Fe3O4 submicrospheres are about 83.5 Oe, 81.2 emu/g and 14.6 emu/g, respectively. The influence of ethylene glycol, concentration of NaOH, and reaction time on the morphology development was experimentally investigated. It was found that ethylene glycol molecules have a significant effect on the formation of Fe3O4 submicrospheres. A possible mechanism was also proposed to account for the growth of these Fe3O4 submicrospheres.