Effect of sintering temperature on microstructure and electrical properties of Ce0.82Dy0.155Sr0.025O2-δ electrolyte

Abstract

Ce0.82Dy0.155Sr0.025O2-δ (SDDC) powder was synthesized by a sucrose-pectin modified sol-gel process. The powder was pressed and sintered at different temperatures, 1200, 1250 and 1300°C, to prepare dense ceramics with a relative density of 91, 93 and 95%TD, respectively. Crystal structure and phase composition were analysed by XRD using Rietveld refinement. The sample compositional analysis and element mapping were carried out by energy-dispersive spectroscopy. Microstructure images were recorded by scanning electron microscope. The electrical properties were measured by an impedance analyser. The grain resistance and the grain boundary resistance changed with the increased grain size. The SDDC electrolyte sintered at 1300°C exhibits an enhanced total electrical conductivity of 2.45×10−2 S/cm at 700°C and the activation energy of 0.76 eV. The porosity corrections are applied to the Bricklayer model to calculate the specific grain and grain boundary conductivities.

Keywords

• doped ceo2
• chemical synthesis
• ceramic microstructure
• electrical conductivity