The Righi-Leduc and Hall coefficients of the noble metals

Abstract

Results of an investigation of the Righi-Leduc and Hall coefficients of pure samples of Cu, Ag and Au over the temperature range 4-125 K are presented. At the lowest temperatures all the samples are in the high field regime ( omega tau >1); in this range the Weidemann-Franz law is found to hold between the thermal and electrical conductivities at the highest fields but is not obeyed for the Righi-Leduc and Hall coefficients, within experimental error, except for Au. Previous data of Hall obtained near room temperature are shown to yield a value very close to the Lorenz number indicative of elastic electronic scattering. The present results are analysed in terms of a two band model, as previously applied to Hall data; it is shown that such a model predicts a variation of the Righi-Leduc coefficient contrary to that observed, except perhaps in the case of Au.