Thermal conductivity of arsenic single crystals from 2 to 300 K

Thermal conductivity of high-quality single crystals of arsenic has been measured along both the binary ($K^{11}$) and trigonal ($K^{33}$) directions between 2 and 300 K. A strong transverse magnetic field was used to separate the lattice ($K_L$) and electronic ($K_E$) thermal conductivity contributions. The lattice conductivity shows significant anisotropy with $K_L^{11}$ exceeding $K_L^{33}$ throughout the temperature range. Both lattice components show $T^2$ behavior below 5 K, but increase more rapidly than $T^2$ in the range $5<T<\mathrm{}15\mathrm{}$ K before reaching maxima in the range 18-25 K. At higher temperatures the lattice conductivity is limited by phonon-phonon umklapp scattering. Below 10 K the electronic thermal conductivity is very sensitive to residual impurities. For $T>\mathrm{}20\mathrm{}$ K, $K_E$ is comparable for all samples and the carrier-phonon scattering is practically isotropic. Experimental values of the Lorenz ratio are significantly smaller than the Sommerfeld value, indicating that the carrier scattering is inelastic in the range 3-80 K.