（1．Key Laboratory for Advanced Ceramic and Machining Technology of Ministry of Education Tianjin University‚300072; 2．School of Chemical Engineering‚Tianjin University）

Abstract：The oxyen－sensing properties of rare earth perovskite complex oxides LaBO3（B＝Ni、Fe、Cr） thin films prepared by means of inorganic－sol－gel（ISG） method using nitrate as raw materials and citric acid as chelating agent had been re- searched．The resistance of LaBO3 was measured as a function of temperature．The curves of resistance－temperature were shown that LaFeO3and LaCrO3thin films possessed the semiconductor nature‚but LaNiO3had low resistivity until800℃ in a manner similar to that of metallic conductor．It was found that the characteristics of d－electron of B ions mainly determined the thin film properties‚that is to say the more activity B ion was‚the better the oxygen－sensing properites of LaBO3 thin film wKaesy．

keywords：inorganic－sol－gel method‚perovskite‚thin film‚oxygen－sensing property