Characteristics and sensing properties of La0.8Pb0.2Fe1−xNixO3 system for CO gas sensors

Nanocrystalline powders of La0.8Pb0.2Fe1−xNixO3 were prepared by a citric method. The structure, electrical and carbon monoxide (CO) gas-sensing properties were investigated. X-ray diffraction patterns showed that the La0.8Pb0.2Fe1−xNixO3 system formed a single phase only when the amount of Ni was lower than x = 0.4. With increasing the Ni amount, the concentration of holes increased, resulting in a decrease in resistance. La0.8Pb0.2Fe0.8Ni0.2O3 showed the highest response to CO, and its electrical resistance was shown to be an exponential function of CO concentration.