Thermal conductivity of arsenic single crystals from 2 to 300 K

Abstract

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 $5lTl15$ 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 $Tg20$ 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.