Influence of the sintering temperature on electrical property of the Ce_0.8Sm_0.1Y_0.1O_1.9 electrolyte

In this study, nano-scale rare-earth co-doped Ce_0.8Sm_0.1Y_0.1O_1.9 material was prepared by the sol-gel method. When sintered after 1300, 1400, 1500 and 1600 °C, the samples all presented well single phase. The SEM result exhibited that when sintered after 1300 and 1400 °C, the pellets were denser with fewer pores than those sintered after 1500 and 1600 °C; and the sample was over-sintered after sintered over 1500 °C. Impedance spectroscopy analyses of the samples sintered at various temperatures were performed at 300-850 °C. And electrical conductivity and activation energy of bulk, grain boundary and the whole electrolyte were calculated. The results displayed that, for all samples treated at different temperatures, the activity energies of grain-boundary conduction all presented higher values (1.02-1.20 eV) than those of the bulk (0.78-0.85 eV); and the samples sintered at 1300 and 1400 °C showed much higher total conductivity and lower activation energy than those sintered at 1500 and 1600 °C. It demonstrated that rare-earth co-doped Ce_0.8Sm_0.1Y_0.1O_1.9 material prepared by the sol-gel method could be easy to sinter at lower temperature dense ceramic electrolyte with better electrical property.