中文摘要：

以La（NO3）3·6H2O、Sr（NO3）2、Co（NO3）2·6H2O为原料，用EDTA络合溶胶．凝胶法制备La0.8Sr0.2CoO3凝胶，在700℃、800℃、900℃煅烧，制得La0.8Sr0．2CoO3粉体。用DTA、FT-IR、XRD、SEM等手段对制备过程、热分解机理及粉体的性能进行了研究。在700℃焙烧2h得到La0.8Sr0.2CoO3纯相纳米粉，颗粒呈球形。选取700℃焙烧2h的La0.8Sr0.2CoO3粉体制成管状传感器，进行NO2敏感性能测试，探讨了相同NO2浓度下，传感器敏感信号与温度的关系。结果表明：纳米La0．8Sr0.2CoO3粉体在450℃时对N02的敏感信号最大，输出的电动势信号与NO2浓度之间呈线性关系。

英文摘要：

Using La（NO3）3-6H2O, Sr（YO3）2, and Co（NO3）2·6H2O as raw materials, the nanometer La0.8Sr0.2CoO3 powders was prepared by EDTA sol-gel method. Gel was calcined at 700 ℃, 800 ℃and 900 ℃ respectively. The samples were characterized by DTA, FT-IR, XRD and SEM techniques. The preparation process, thermal decomposition mechanism and performances of the powders have been studied. The results show that the spheric nanocrystalline La0.8Sr0.2CoO3 could be obtained after calcined at 700 ℃ for 2 h. The tube-type NO2 sensor was prepared with La0.8Sr0.2CoO3 powder calcined at 700 ℃ for 2 h as sensing material and its performance was tested. The results show that at 450℃ the sensor is the most sensitive to NO2. At a fixed temperature, EMF responses and NO2 concentrations are of linear relationship.