Thermal diffusivity and conductivity of Zr1−xYxO2−x/2 (x=0, 0.084 and 0.179) single crystals

The thermal diffusivity of Zr1−xYxO2−x/2 (x=0, 0.086 and 0. 0.179) single crystals has been determined up to 1100 °C with a laser flash method designed to minimize radiative transfer effects. The thermal conductivity of these materials can be satisfactorily described in the framework of the phonon theory, provided a minimum phonon mean free path is introduced. Both experimental results and a theoretical approach indicate that for this system, and in the composition range explored, the high temperature limit of the thermal conductivity does not depend on the constitutional point defect content. The point defects influence the decrease of the thermal conductivity at intermediate temperatures.