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 5 mol%. The sintered density was found to increase rapidly up to 0.5 mol% Sr2Ga2O5, and then to decrease with further additions. Dense Ce0.8Sm0.2O1.9 ceramics with 97% of the theoretical density could be obtained for 0.5 mol% Sr2Ga2O5-added specimen sintered at 1250 °C for 5 h, 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 0.5 mol% Sr2Ga2O5-added specimen showed the maximum conductivity of 1.91 × 10−2 Ω−1 cm−1 at 500 °C. The addition of strontium gallate was found to promote the sintering properties and electrical conductivities of Sm2O3-doped CeO2.