The electrical resistivity of liquid bismuth, gallium and bismuth-gallium alloys

Abstract

The electrical resistivities of bismuth, gallium and bismuth-gallium alloys have been measured over the whole phase diagram in ten atomic per cent steps, from the liquidus to 1100°C. The electrical resistivities of the pure components have been computed at different temperatures using Ziman's formula with various model potential form factors and experimental or hard-sphere structure factors. For the alloys, the measurements are compared with the values obtained from the Faber-Ziman formula. We followed Ashcroft and Langreth for the description of the partial structure factors and used the local potentials of Harrison and Ashcroft and the non-local potentials of Heine and Abarenkov, Animalu and Heine, and Appapillai and Williams. The theoretical results are generally in good agreement with the experimental values on the gallium side of the phase diagram. They are less good for bismuth-rich alloys for which the ratio between the mean free path and the interatomic distance tends to 1 7. Here we are at the limit of the validity of the Born approximation and perturbation theory. However the potential of Appapillai and Williams gives a good result.