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采用共沉淀法制备了一系列Fe掺杂含量由低到高的纳米晶SnO2粉体。采用X射线衍射、透射电镜、X射线光电子谱分析等测试手段对其进行了表征。结果表明:当Fe掺杂含量(摩尔分数)低于15%时,晶粒大小随掺杂含量的增加显著下降,从无掺杂的5.2nm到掺杂15%Fe的2.4nm,随后继续增加Fe掺杂含量对晶粒大小无影响。而当Fe掺杂量大于20%时,Fe在SnO2晶粒表面才出现较为明显的偏析。掺杂物对SnO2晶粒长大的阻碍作用主要归因于掺杂物与SnO2体相形成固溶体,产生的溶质拖曳和晶格畸变效应,掺杂物在晶粒表面偏析所起作用较小。
A series of nanocrystalline SnO2 powders with low Fe content were prepared by coprecipitation method. It was characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The results show that the grain size decreases obviously with increasing doping content from 5.2nm to 2.4nm doped with 15% Fe when the content of Fe doping (mole fraction) is less than 15%, then continues to increase Fe doping content has no effect on the grain size. When the doping amount of Fe is more than 20%, the obvious segregation appears on the surface of SnO2. The obstruction effect of dopants on the grain growth of SnO2 is mainly attributed to the solute drag and lattice distortion effect caused by the dopant and SnO2 bulk phase. The dopant has little effect on grain surface segregation.