Ref. reports total thermal conductivities of 4 and 3 W m -1 K -1 at 300 and 1000 K, respectively, while Ref. reports a larger 6.5 W m -1 K -1 at 400 K and a comparable κ = 3.25 W m -1 K -1 at 1000 K. Neither study attempts to separate the κ el and κ latt , but the reasonable agreement at 300 K possibly suggests a larger κ el than the < 1 W m -1 K -1 predicted in the calculations in the previous section. If this is the case, we would expect the κ to be somewhat sensitive to the sample preparation conditions and resulting carrier concentration, which would provide an explanation for why Ref. reports a ∼ 60% larger κ at 400 K than Ref. at 300 K. On the other hand, comparison to the measurements in Ref. , which obtained κ latt ≈ 2 -4.5 and 2-3 W m -1 K -1 at 300 and 1000 K, suggest that our calculations underestimate the κ latt at high temperature. We note that, while we might expect the phase transition in STO to account for part of the discrepancy between our calculations and experiments, the orthorhombic-to-cubic transition in CTO occurs well above 1000 K, so this is unlikely to be an issue for this system.