Lattice Conductivity of Tin

The thermal conductivities of several impure tin specimens have been measured at liquid helium temperatures. Impurities of antimony, bismuth, and indium between 0.1% and 6% were used to lower the electronic conductivity. The conductivities are found to be consistent with the equation K=αT+βT², where the first term may be ascribed to the electronic conductivity and the second to the lattice conductivity. For impurities of 3% or less the values of α, combined with measurements of the residual electrical resistivity, agree to about one percent with the prediction of the Wiedemann-Franz law. For the same samples β is approximately constant with a mean value of (3.5±{}0.4)×{}10^-4 watt/cm deg³. The comparative constancy of this value of β indicates that it is characteristic of the intrinsic conductivity of the tin lattice.