Electrical conductivity of Y-doped CGO based materials sintered by hot press

Abstract

Commercial ceria–gadolinia powders were used to prepare dense CGO (5 mol% Gd) samples, by hot press method at relatively low temperature (1000°C). To study the effect of post-sintering, further the as-sintered bodies were subjected into different thermal treatments 1100oC-1400oC. The sintered samples were characterized by impedance spectroscopy as a function of temperature in air, in order to identify each microstructural contribution to the overall electrical behaviour. Scanning electron microscopy shows that the increase in the temperature of thermal treatment leads to grain growth. Electrical properties were studied with different oxygen partial pressuresand ion blocking methods. Y2O3 (5 wt%) additions were used to seek the grain boundaries heterogeneities effectsin CGO material, prepared by hot press and subjected into post sintering thermal treatments. Electrical conductivities of CGO samples were analysed with and without Y2O3 additions.