Structure, electrical and CO-sensing properties of the La0.8Pb0.2Fe1−xCoxO3 system

Ultrafine powders of La0.8Pb0.2Fe1−xCoxO3 were prepared by a citric method. The structure, electrical and CO gas-sensing properties were investigated. X-ray diffraction patterns showed that the La0.8Pb0.2Fe1−xCoxO3 system formed a single phase only when the amount of Co was lower than x = 0.4. With increasing the Co amount, the concentration of holes increased, resulting in an increase in conductivity. La0.8Pb0.2Fe0.8Co0.2O3 showed the highest response to CO, and its electrical resistance was shown to be an exponential function of CO concentration.