The lattice thermal conductivity between 1.7 and 150 K of $p$-type mercury telluride is reported. For most of this temperature range the thermal-conductivity behavior is similar to that of other valence or ionic crystals, but at the lowest temperatures the thermal conductivity is limited, not by boundary scattering of phonons, but apparently by hole-phonon scattering. The Callaway phenomenological model is used to fit the data and to obtain the magnitudes of the normal-, umklapp-, and Rayleigh-scattering relaxation times. Although the hole concentrations of the samples ranged from 5.0 × ${10}^{16}$ to 4.4 × ${10}^{18}$ ${\mathrm{cm}}^{-3\mathrm{}}$, the magnitude of the inverse relaxation time for the scattering of phonons by holes did not vary significantly and was approximately $2.7q$ ${\sec }^{-1\mathrm{}}$ for the phonon wave number $q$ less than 6 × ${10}^6$ ${\mathrm{cm}}^{-1\mathrm{}}$. This behavior is attributed to the complex shape of the hole Fermi surface. As the hole concentration of HgTe increases, the maximum dimension of the hole Fermi surface increases relatively slowly because of the overlapping valence and conduction bands, and thus the range of wave numbers of phonons which can interact with holes is only weakly dependent upon the density of holes. Measurements of the thermoelectric power also are reported, and the same hole-phonon-scattering relaxation time required to explain the low-temperature thermal conductivity accounts for the phonon-drag contribution to the thermoelectric power.

• Received 25 August 1971

DOI:https://doi.org/10.1103/PhysRevB.5.3125