Heat capacities and thermal conductivities of perovskite type BaZrO 3 and BaCeO 3

Abstract

Polycrystalline perovskite type oxides, BaZrO 3 and BaCeO 3, have been prepared by mixing the appropriate amounts of ZrO 2, CeO 2, and BaCO 3 followed by reacting at 1273 K and sintering at 1773 K. The thermal conductivities of BaZrO 3 and BaCeO 3 have been evaluated from the heat capacity, thermal diffusivity, and density. The heat capacity has been measured by using a differential scanning calorimeter (DSC) in a high purity argon atmosphere. In the temperature range from room temperature to about 1400 K, the thermal diffusivity has been measured by a laser flash method in vacuum. The thermal conductivities of both BaZrO 3 and BaCeO 3 decrease with increasing temperature, showing phonon conduction characteristics. The thermal conductivity at room temperature of BaZrO 3 is 5.2 Wm −1K −1, which is about 3 times larger than that of BaCeO 3.