A ZrO2-based electrolyte which was stabilized with 6mol%CaO and 4mol%Y2O3 was synthesized. The electrolyte consisted of a single-phase fluorite-type solid solution of cubic symmetry, and had a uniform microstructure. At 1273 to 1673K, the direct-current conductivity of this electrolyte was higher than that of 12mol%CaO-stabilized ZrO2 and was comparable to that of 8mol%Y2O3-stabilized ZrO2 which had been prepared under the same processing conditions. It was suggested, after comparing the electrical behaviors of the binary systems, ZrO2-CaO and ZrO2-Y2O3, that the enhancement of the ionic conductivity of mixed CaO-Y2O3 stabilized ZrO2 at high temperatures could be attributed to an increase in the concentration of O vacancies with weaker association energies.

Enhancement of the Ionic Conductivity of Mixed Calcia/Yttria Stabilized Zirconia. J.Gong, Y.Li, Z.Tang, Z.Zhang: Materials Letters, 2000, 46[2-3], 115-9