Thermophysical properties of perovskite type alkaline-earth metals and plutonium complex oxides

Polycrystalline specimens of strontium plutonate, SrPuO 3 , have been prepared by mixing the appropriate amounts of PuO 2 and SrCO 3 powders 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 elastic moduli of SrPuO 3 were determined from the longitudinal and shear sound velocities. The Debye temperature was also determined from the sound velocities and lattice parameter measurements. The thermal conductivity of SrPuO 3 was calculated from the measured density at room temperature, literature values of heat capacity, and thermal diffusivity measured by laser flash method in vacuum. Although the thermal conductivity of SrPuO 3 slightly decreased with increasing temperature to 800 K, the range of change was extremely narrow and the temperature dependence did not completely follow the 1/ T law. The thermal conductivity of SrPuO 3 was lower than those of other perovskite type oxides.