Phonon-Drag Thermoelectric Power and Low-Field Hall Coefficient of Copper

Abstract

The electrical conductivity σ, the phonon-drag thermoelectric power S L , and the low-field Hall coefficient R of copper are calculated with the variational method. The band structures of Burdick and the measured phonon spectrum are used in the calculation. The parameters in the electron-phonon coupling are adjusted to the observed electrical conductivity. The room-temperature value of R is smaller than the observed one by 20%, and this discrepancy may be ascribed to the large s - d hybridization in Burdick's bands. The temperature dependence of R agrees reasonably well with the observation above 50°K. It is noted that below 50°K, existing measurements for pure samples do not satisfy the low-field condition. The phonon-drag effects on σ and R are proved to be negligibly small. The calculated value of S L is positive above 30°K and large enough to explain the observed hump around 70°K, while it becomes negative below about 30°K, consistent with the experimental results.