不同形貌Fe_3O_4纳米粒子的氧化沉淀法制备与表征

Preparation and Characterization of Magnetite Nanoparticles with Various Morphologies by One Method

用一种方法成功合成出了球体、四方体、八面体、不规则多面体、三角形和不规则颗粒等六种具有不同形貌的Fe3O4纳米粒子,通过扫描电子显微镜(SEM)表征了粒子形貌。试样经过X-射线衍射(XRD)表征具有尖晶石结构,且结晶良好。经震动样品磁强计(VSM)测定,各种形貌的Fe3O4纳米粒子都具有良好的磁性,其中八面体形貌的Fe3O4纳米粒子的饱和磁化强度达到86.56emu·g-1,剩磁为10.64emu·g-1,矫顽力为138Oe。讨论了不同形貌的Fe3O4纳米粒子的形成机制,得出了晶核的生长环境对纳米粒子的形貌有重要影响的结论。

Magnetite nanoparticles with various morphologies as sphere, cube, regular octahedron, irregular polyhedron, triangle and irregular grains have been successfully synthesized by using only one preparation method with FeSO4·7H2O and NaOH as starting materials. X-ray diffraction （XRD）, scanning electron microscope （SEM） and vibrating sample magnetometer （VSM） techniques were used to characterize the as-synthesized magnetite nanoparticles for their structure, shape and magnetic properties, respectively. The results show that all the assynthesized magnetite nanoparticles, are well crystallized and can be indexed into spinel structure. The saturation magnetization of octahedral magnetite nanoparticles is 86.56 emu. g^-1; the remanence magnetization and coercive forces of octahedral magnetite nanoparticles are 10.64 emu·g^-1, 138 Oe, respectively. The possible mechanism for the formation of magnetite nanoparticles with various morphologies is suggested.