Thermal conductivity of BaZrO3 and KTaO3 single crystals

Abstract

BaZrO3 and KTaO3 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 BaZrO3, the κ of 7.5 Wm−1K−1 at 300 K is ∼40% larger than the previously reported polycrystalline values. For KTaO3, our value of 13.1 Wm−1K−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.