Thermal conductivity of BaPuO3 at temperatures from 300 to 1500 K

Polycrystalline specimens of barium plutonate, BaPuO3, have been prepared by mixing the appropriate amounts of PuO2 and BaCO3 followed by reacting and sintering at 1600 K under the flowing gas atmosphere of dry-air. The sintered specimens had a single phase of orthorhombic perovskite structure and were crack-free. The Debye temperature of BaPuO3 was determined from the sound velocity and lattice parameter measurements. The elastic moduli were also determined from the longitudinal and shear sound velocity. The thermal conductivity of BaPuO3 was calculated from the measured density at room temperature, literature values of heat capacity, and thermal diffusivity measured by a laser flash method in vacuum. The thermal conductivity of BaPuO3 was roughly independent of the temperature and was almost the same magnitude as that of BaUO3. This was markedly lower than the conductivities of other perovskite type oxides and was about one-tenth that of UO2 around room temperature. The temperature dependence of the thermal conductivity of BaPuO3 was found to be quite similar to that of BaUO3.