Effects of the gas flow rate on the ionic conductivity of CaZr 0.95In0.05O3-δ ceramics

Abstract

With coarse CaCO3, nano ZrO2 and In2O 3 as raw materials, fine CaZr0.95In0.05O 3-δ powders were synthesized at 1000°C by an optimized solid-state method. With the powders, ceramics with relative density as high as 98% were successfully fabricated at the temperature as low as 1400°C. The effects of gas flow rate on the conductivity of the CaZr0.95In 0.05O3-δ ceramics under wet air conditions were first studied. The results showed that with the increase of temperature, the effects became more and more significant. In order to gain insight into the ion transfer mechanism of the electrolyte, the absorption and diffusion processes were analyzed. It was suggested that at lower temperature, the diffusion step was the rate-determining step. However, with the increase of the temperature, the adsorption process became the rate-determining step at lower flow rates. © 2007 Springer Science+Business Media, LLC.