纳米晶La_(0.7)Pb_(0.3)FeO_3的制备 及其对CO敏感特性的研究

Preparation and CO Sensitivity of Nanocrystalline La_(0.7)Pb_(0.3)FeO_3-Based Gas Sensor

摘要:

利用溶胶-凝胶法制备了纳米晶La0.7Pb0.3FeO3气敏材料,并对其相组成、电导及其对CO气敏性能进行了研究。XRD结果表明:掺铅固溶体La0.7Pb0.3FeO3仍为正交晶系钙钛矿结构,粒径约为17nm,低于纯相LaFeO3的粒径31nm。电导测量显示:该材料呈p型半导体导电行为,电导大于同温度下纯相LaFeO3的电导,且电导突变温度有所降低。气敏性能研究表明:Pb掺杂对其CO气敏性能有了明显改善。

Abstract:

This paper reports that nano- La0.7Pb0.3FeO3 powders can be used as a new type of gas-sensing material for detecting CO. The La0.7Pb0.3FeO3 powders were prepared by a citric method. The powders are characterized by X-ray diffraction, showing that the La0.7Pb0.3FeO3 is still perovskite phase with orthorhombic structure and its crystallite size is about 17 nm, smaller than that of LaFeO3. The La0.7Pb0.3FeO3 is a kind of p-type semiconductive material, and its conductivity is higher than that of LaFeO3. The CO sensitivity of La0.7Pb0.3FeO3-based sensor is investigated. We found that La3+ partly substituted by Pb2+ in LaFeO3 can enhance its sensitivity for CO gas.