Fe掺杂对纳米晶SnO_2粉体结构的影响(英文)

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。

EFFECT OF Fe-DOPING ON NANOSTRUCTURE CHARACTERISTIC OF SnO2 NANOPOWDERS PREPARED BY CO-PRECIPITATION METHOD

A series of Fe-doped SnO2 nanopowders with various dopant concentrations were prepared by a chemical co-precipitation technique, and the as-prepared nanopowders were characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoeledron spectroscopy. The results show that the doping of Fe can obviously prevent the growth of nanosized SnO2 crystallites. The average crystallite size is 5.2 nm for undoped SnO2, and it decreases to 2.4 run significantly when the mole fraction of Fe dopant is 15%. However, as the doping mole fraction of Fe reaches or surpasses 15%, SnO2 crystallite size reaches a minimum value and remains almost constant. When the mole fractions of doping Fe are higher than around 20%, the segregation of Fe on the surface of SnO2 is observed. The effect of Fe doping on hindering crystallite growth may be attributed to the solute drag and lattice distortion resulting from Fe dissolving in the bulk phase of SnO2 to form solid solution, rather than segregation of Fe on the surfaces of the SnO2 powders.