摘要
采用化学共沉淀法，制备了系列ＣｄＯ－Ｆｅ２Ｏ３复合氧化物气敏半导体材料，研究了制备条件对电导和气敏性能的影响．结果表明：组分氧化物之间在２５０℃开始发生反应；Ｃｄ／Ｆｅ＝１／２共沉淀粉料在６００℃时形成单一尖晶石ＣｄＦｅ２Ｏ４相；电导率和气敏性能随材料体系的化学组成及烧成温度不同而变化；Ｃｄ／Ｆｅ为１／２产物对乙醇有最高灵敏度和很好的选择性；优化制备工艺制得的气敏元件，对低浓度乙醇气体（１００ｐｐｍ）灵敏度高达２０多倍，相当于１０００ｐｐｍ汽油灵敏度的５倍左右，具有应用开发前景．
A series of CdO Fe 2O 3 system gas sensing semiconducting materials are prepared by a chemical coprecipitation method. It is found that the reaction between CdO and Fe 2O 3 begins at 250℃ and a pure spinel CdFe 2O 4 phase is obtained at 600℃. The conductance and gas sensing properties are strongly related to the material compositions and synthetical conditions. The element made of the powder with Cd/Fe=1/2 and calcined at 800℃ exhibits the highest sensitivity and best selectivity to ethanol. The gas sensitivity to 100ppm ethanol was more than 20, which is close to 5 times of that to 1000 ppm petrol. This demonstrates its promising value for practical use.
基金
国家自然科学基金
