Effects of strontium gallate additions on sintering behavior and electrical conductivity of samaria-doped ceria

The densification behavior and electrical conductivity of Ce0.8Sm0.2O1.9 ceramics were investigated with the strontium gallate concentration ranging from 0 to 5mol%. The sintered density was found to increase rapidly up to 0.5mol% Sr2Ga2O5, and then to decrease with further additions. Dense Ce0.8Sm0.2O1.9 ceramics with 97% of the theoretical density could be obtained for 0.5mol% Sr2Ga2O5-added specimen sintered at 1250°C for 5h, whereas pure Ce0.8Sm0.2O1.9 ceramics needed to be sintered at 1550°C in order to obtain an equivalent theoretical density. Electrical conductivity was measured as a function of dopant content, over the temperature range of 350–550°C in air. Total conductivity of 0.5mol% Sr2Ga2O5-added specimen showed the maximum conductivity of 1.91×10−2Ω−1cm−1 at 500°C. The addition of strontium gallate was found to promote the sintering properties and electrical conductivities of Sm2O3-doped CeO2.