Electrical resistivity of liquid copper-silver alloys

Abstract

The electrical resistivity of copper-silver has been measured over the whole phase diagram in ten at.% steps, from the liquidus to 1150°C. Our measurements, made in a quartz cell fitted with four tungsten electrodes, are compared with the values obtained earlier by Roll and Motz using the electrodeless technique. Our measurements do not reproduce the anomalies obtained by Roll and Motz in curves of the resistivity and in its temperature coefficient against concentration. Our experimental data are interpreted using the Faber-Ziman formula. We followed Ashcroft and Langreth for the description of the partial structure factors and used form factors deduced from the pseudopotentials, which take into account the d band, as in Moriarty and Animalu. These potentials are given for pure metals; in the case of alloys we renormalized the form factor by taking into account the atomic volume of the alloy. We also used the extended Faber-Ziman formula where the form factor is simply replaced by a t-matrix expressed in terms of phase shifts. The resistivity and its temperature coefficient against concentration are compared with theory using both types of form factors.