Thermal diffusivity of MgSiO3 perovskite

Thermal diffusivity of MgSiO3 perovskite has been measured in the temperature range of 160 K to 340 K using a sample synthesized in a uniaxial split‐sphere high‐pressure apparatus. At 300 K the thermal diffusivity of perovskite is 1.72 × 10−6 m2s−1, from which the thermal conductivity is evaluated to be 5.1 Wm−1K−1. Our model calculation shows that lattice thermal conductivity of the perovskite increases by a factor of 4 with depth throughout the lower mantle and reaches to 12 Wm−1K−1 in the vicinity of the mantle‐core boundary. The D″ layer might not be a thermal boundary layer insulating the high core‐temperature, if this layer mainly consists of the perovskite.