The effects of temperature and composition on the thermal conductivities of [(ZrO2)1−x(CeO2)x]0.92(Y2O3)0.08 (0 ⩽ x ⩽ 1) solid solutions

The thermal conductivities of [(ZrO2)1−x(CeO2)x]0.92(Y2O3)0.08 (0 ⩽ x ⩽ 1) solid solutions are studied in this paper. The incorporation of ZrO2 and CeO2 in the solid solution decreases the thermal conductivity compared with their end members (YSZ and YDC). The thermal conductivities of the solid solutions show clearly different temperature dependences in the ZrO2-rich (0 ⩽ x ⩽ 0.5) region and in the CeO2-rich region (0.5 ⩽ x ⩽ 1). The composition and the temperature dependence of the thermal conductivities are discussed based on established phonon scattering theories. We have concluded that the composition dependence of the thermal conductivity of this system is mainly controlled by the mass difference between Zr4+ and Ce4+, while the thermal conductivity-temperature relationship is dominated by the randomness of the defect distribution.