Zou Guifu, Xiong Kan, Jiang Changlong, Li Hui, Li Tanwei, Du Jin, Qian Yitai
Hefei National Laboratory for Physical Science at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, P R China.
J Phys Chem B. 2005 Oct 6;109(39):18356-60. doi: 10.1021/jp052678c.
Fe3O4 novel fractal nanocrystals have been synthesized by a surfactant-assisted solvothermal process for the first time. X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), Mössbauer spectroscopy (MS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) have been used to investigate the novel fractal nanocrystals. The lengths of the fractals are about 2-3 microm, and the trunks and branches of Fe3O4 fractals have almost the same diameters of ca. 30-50 nm. The roles of surfactant PEG-20000 and N2H4 have been discussed in detail. One key fact has been found that the ferrocene concentration has a vital effect on the morphologies of the products. The side-branching process and the oscillation of the concentration have been proposed to illustrate the formation mechanisms of the fractal nanocrystals. In addition, magnetic properties of Fe3O4 fractal nanocrystals have also been detected by a vibrating sample magnetometer, showing relatively high saturation magnetization (Ms) of ca. 78.75 emu/g.
首次通过表面活性剂辅助溶剂热法合成了Fe3O4新型分形纳米晶体。利用X射线衍射（XRD）、X射线光电子能谱（XPS）、穆斯堡尔谱（MS）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对新型分形纳米晶体进行了研究。分形的长度约为2-3微米，Fe3O4分形的主干和分支直径几乎相同，约为30-50纳米。详细讨论了表面活性剂PEG-20000和N2H4的作用。发现了一个关键事实，即二茂铁浓度对产物的形态有至关重要的影响。提出了侧支化过程和浓度振荡来解释分形纳米晶体的形成机制。此外，还通过振动样品磁强计检测了Fe3O4分形纳米晶体的磁性，显示出约78.75 emu/g的相对较高的饱和磁化强度（Ms）。
