Thermal conductivity of BaZrO3 and KTaO3 single crystals

Abstract BaZrO 3 and KTaO 3 are two rare examples of perovskite oxides that retain the ideal cubic structure down to the lowest temperature. In this paper, we report thermal conductivity (κ) between 300 and 773 K on single crystals of these compounds. For BaZrO 3 , the κ of 7.5 Wm −1 K −1 at 300 K is ~40% larger than the previously reported polycrystalline values. For KTaO 3 , our value of 13.1 Wm −1 K −1 at 300 K clarifies the sources of error in some of the previously reported data. These results underscore the importance of high-quality experimental data in benchmarking the accuracy of advanced first-principles κ calculations.