Thermal diffusivity of uranium monosulfide from 638 to 1823 K

The thermal diffusivity of uranium monosulfide was determined between 628 and 1823 K by a laser pulse method. Values for the thermal conductivity at 638 and 1823 K, calculated from the available data of the heat capacity, and corrected to theoretical density, were found to be 0.117 and 0.192 W/cm · K respectively. They were fitted to the sum of the electronic contribution and the lattice contribution to the thermal conductivity. The electrical resistivity was calculated by means of the Wiedeman-Franz law, using the Lorenz number for metallic conductors, assuming that the electronic part of the thermal conductivity was represented by the subtraction of the phonon part of the thermal conductivity, fitted by a computer, from the total thermal conductivity. The results agreed well with those of the direct measurements of electrical resistivity by other investigators. The Grüneisen anharmonicity parameter was also calculated from the value of the lattice contribution to the thermal conductivity, to be 1.07.