Ionic conductivity in the ternary system (ZrO2)1−0.08x−0.12y–(Y2O3)0.08x–(CaO)0.12y

The total electrical conductivity of the samples in the ternarysystem (ZrO2)1-0.08x-0.12y–(Y2O3)0.08x–(CaO)0.12y was measured by adirect current four-probe method in the temperature range 773 to1673 K. It was found that partial replacement of Y2O3 by CaO in thesystem ZrO2–Y2O3 may enhance the electrical conductivity at highertemperatures. At lower temperatures, however, doping CaO as the thirdcomponent into the system ZrO2–Y2O3 depresses the conductivity. Theobserved mixed dopant effect was then analyzed by considering thecombined effect of both parameters appeared in the traditionalArrhenius equation, the activation energy, E, and the preexponentialfactor, σ0, on the temperature-dependence of the measured conductivity.