A limiting current oxygen sensor based on (La0.4Ce0.6O2-δ)0.96(FeO1.5)0.04 as dense diffusion barrier

Abstract

(La0.4Ce0.6O2-δ)0.96(FeO1.5)0.04 ((LCO)0.96(FeO1.5)0.04) and Y0.08Zr0.92O2 (8YSZ) powders were prepared by co-precipitation and used as dense diffusion barrier and solid electrolyte materials of a limiting oxygen sensor fabricated by a co-pressing and co-sintering method, respectively. The crystalline structure, conductivity, fracture characteristics, distribution of elements, and sensing performance of the prepared sample were characterized. The results show that the electronic and ionic conductivities of (LCO)0.96(FeO1.5)0.04 are 2.86 × 10−4 and 2.16 × 10−2 S cm−1 at 850 °C, respectively, satisfying the requirement of dense diffusion barrier. The SEM-EDS analysis shows an excellent bonding property between solid electrolyte and dense diffusion barrier, and a homogeneous distribution of elements without evident diffusion. The oxygen sensor exhibits a stable sensing performance. The limiting current shows a linear relation with the oxygen concentration, and an exponential relation with the inverse temperature.