Thermal Conductivity of $1T$-Ta${\mathrm{S}}_2$ and $2H$-Ta${\mathrm{Se}}_2$

We present measurements and analysis of the basal thermal conductivity for two dichalcogenides: $1T$-Ta${\mathrm{S}}_2$ and $2H$-Ta${\mathrm{Se}}_2$. The data which are obtained for the first time cover the range 80-400 K. The lattice contribution is important for each compound and possesses specific features related to charge-density-wave-type transitions; in particular, that of Ta${\mathrm{S}}_2$ exhibits a quite unusual upward jump. For Ta${\mathrm{Se}}_2$ we use an order-disorder picture to explain both the lattice conductivity and the entropy variation in unison with the electrical resistivity.