Thermal conductivity of alloys of the bismuth-antimony system in solid and liquid states

Abstract

1. Thermal conductivity of Bi-Sb alloys increases at melting approximately by the same magnitude as in pure bismuth (λs/λl = 0.5−0.8). Moreover, this increase of λ occurs not in jumps, as in pure metals and compounds, but smoothly, at transition from the solid into the liquid state, in accordance with the phase diagram. 2. In the liquid state, the λ of alloys continues to increase comparatively sharply despite the observed decrease of electrical conductivity. This is, possibly, an indication of the participation of the mechanism of bipolar diffusion in heat transfer. 3. The presence of the contribution of bipolar thermal conductivity within the range of 15–30%, depending on the composition of the tested specimens, was established by studying the effect of the magnetic field on thermal conductivity at 45–200 °C. According to our calculations, the phononic proportion amounts to 20–35%.