In this thesis,using high energy ball mill method and orthogonal experiment design,SnO2 nanopowder and La2O3 nanopowder were milled and mixed.Therefore,pure SnO2 nanopowder and La2O3 doped-SnO2 nanopowder were prepared.SnO2 thick-film gas sensors and La2O3-doped SnO2 thick-film gas sensors were show that,the primary and secondary sequence affecting the comprehensive gas-sensing properties is： La2O3-doping concentration sintering time aging time sintering temperature.By analysis,an optimum preparation condition was found.Gas sensors exhibit the best comprehensive gas-sensitive properties when the preparation condition was： La2O3-doping concentration 5wt%,sintering time 2h,aging time 7d and sintering temperature 650℃.The sensitivity to 1.0×-3 ethanol vapor is 107.2,and the best selectivity to interference gas（gasoline vapor or acetone vapor） with the same concentration is Sethanol/Sgasoline=11.3,Sethanol/Sacetone=9.1,respectively.%以SnO2纳米粉和La2O3纳米粉为原料,采用高能球磨技术,结合正交试验设计,制备了经过高能球磨的纯SnO2纳米粉体和掺杂适量La2O3的SnO2纳米粉体。利用传统的厚膜气敏传感器制备工艺,制备了纯SnO2厚膜气敏传感器及掺杂一定量La2O3的SnO2厚膜气敏传感器。并对其本征电阻及其对乙醇、汽油、丙酮、氢气和CO等气体的敏感特性进行了测试。结果表明各因素对综合气敏性能影响的显著性水平由大到小依次为La2O3掺杂浓度〉烧结时间〉老化时间〉烧结温度。同时,通过分析还得到了最佳组合工艺。La2O3掺量为5%（质量分数）,烧结时间为2h,老化时间为7d,烧结温度为650℃条件下制备的气敏元件的综合气敏性能最好,其中对1.0×10-3乙醇蒸气的灵敏度达107.2,对相同浓度的干扰气体的选择性分别为S乙醇/S汽油=11.3,S乙醇/S丙酮=9.1。
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