介绍掺入Sb_2O_3后的SnO_2和FeO_3(由γ-Fe_2O_3-热处理得到)气敏厚膜元件电阻和灵敏度的变化规律:对于SnO_2基元件,Sb_2O_3具有低掺杂(<4%wt)电阻变小,高掺杂电阻增大的作用,但气敏性降低;对于Fe_2O_3基元件,掺入Sb_2O_3后不但能降低电阻、提高气敏性,而且对丙酮的选择性也增强.指出Sb~(3+)→Sb~(5+)变化对上述效应起着重要作用,并探讨了Fe_2O_3基元件表面化学吸附增强的原因. The variation of electrical resistance and sensitivity of SnO_2 and FeO_3 doped γ-Fe_2O_3-treated gas-sensing thick-film elements after introducing Sb_2O_3 is introduced. For SnO_2-based elements, Sb_2O_3 has low doping (<4% wt) High doping resistance but low gas sensitivity. For Fe 2 O 3 -based elements, not only the resistance but also the gas sensitivity were improved and the selectivity to acetone was also enhanced after Sb 2 O 3 was incorporated. → The change of Sb ~ (5+) plays an important role in the above-mentioned effect, and the reason for the increase of chemisorption on the surface of Fe_2O_3-based element is also discussed.