α-Fe2O3掺杂对In2O3电导和气敏性能的影响

用化学共沉淀法制备了α Fe2O3掺杂的In2O3纳米晶微粉,研究了α Fe2O3掺杂对In2O3电导和气敏性能的影响. 结果表明, α Fe2O3和In2O3间可形成有限固溶体In2－xFexO3(0≤x≤0.40); Fe3＋对In2O3晶格中In3＋格位的部分取代,大大增强了阴阳离子间的结合力,导致材料中氧空位VO×数骤降、 自由电子的浓度变稀和电导下降. n(Fe3＋):n(In3＋)=5 :5的共沉淀粉于800 ℃下灼烧4 h所得的α Fe2O3掺杂In2O3传感器元件,对45 μmol•L－1 C2H5OH的灵敏度达54.0,为相同浓度干扰气体汽油的8倍多.

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Nanocrystalline powder of In2O3 mixed with α Fe2O3 is prepared by chemical coprecipitation, effects of α Fe2O3 on the conductance and gas sensing properties of In2O3 are investigated. The results demonstrate that partial solid solution In2－xFexO3（0≤x≤0.40）can be formed between α Fe2O3 and In2O3; Partial lattice substituting of Fe3＋ to In3＋ can notably enhance the combining force between anion and cation, it causes oxygen vacancy to decrease, free electron density to be reduced and the conductance to be poorer(to see Fig.2). The sensitivity of sensor, which is prepared with 5:5 n(Fe3＋) andn(In3＋) calcined at 800 ℃ for 4 h, to 45 μmol•L－1 C2H5OH can reach the value of 54.0. This is eight times more than that of petrol with the same concentration .