Lattice Thermal Conductivity of Mercury Selenide

Abstract

The lattice thermal conductivity between 1.7 and 270 K is reported for single crystals of mercury selenide having conduction electron concentrations from 2.1×${10}^{17}$ to 6.7×${10}^{18}$ ${\mathrm{cm}}^{-3\mathrm{}}$. The most striking feature of the data for HgSe is the pronounced depression of the magnitude of the thermal conductivity between 4 and 30 K, and this is attributed to the Wagner mechanism for third-order phonon-annihilation resonance scattering of phonons. The data were analyzed by using the Callaway formalism to determine the relaxation times for phonon scattering by normal and umklapp processes, point defects, resonance modes, crystal boundaries, and conduction electrons. The resonance dip in thermal conductivity was observed in variously prepared HgSe samples, including specially purified and vapor-deposited crystals. Addition of sulfur impurity to HgSe apparently enhanced the resonance scattering, but because sulfur considerably altered the normal and umklapp scattering it could not be concluded is substitutional sulfur atoms were the resonantly scattering centers or if they only indirectly affected the resonance. The ionized defects in HgSe, in concentrations corresponding to as many as ${3\times 10}^{18}$ conduction ${\mathrm{e}\mathrm{l}\mathrm{e}\mathrm{c}\mathrm{t}\mathrm{r}\mathrm{o}\mathrm{n}\mathrm{s}/\mathrm{c}\mathrm{m}}^3$, acted as point Rayleigh scattering centers, but there was no increase in the Rayleigh scattering as the electron concentration was increased above ${3\times 10}^{18}$ ${\mathrm{cm}}^{-3\mathrm{}}$.