Thick films of In, Bi and Pd metal oxides impregnated in LaCoO3 perovskite as carbon monoxide sensor

Abstract Thick films of LaCoO 3 perovskite and metal oxides (In, Bi and Pd) impregnated in LaCoO 3 have been used as sensor materials for sensing temperature and carbon monoxide gas. LaCoO 3 has shown good characteristics of a thermal sensor up to 500 °C. The thermal sensitivity is decreased considerably by the impregnation of metal oxides and it has shown very low with PdO and Bi 2 O 3 . The sensor response for CO is quite good with a good recovery for the partial pressures from 10 to 40 ppm at 200 and 250 °C. LaCoO 3 has exhibited good response in spite of low sensitivity and better recovery even at 200 °C for 10 ppm partial pressure of CO. Higher partial pressures have given higher sensor responses. Probable mechanisms have been proposed in the light of present investigation and the earlier work.