Low-temperature transport properties of the alkali metals II. The transport coefficients

Abstract

The theory of part I (Collins 1961) is applied to the direct calculation of the ‘ideal’ electrical and thermal resistivities and ‘phonon drag’ thermo-electric power, of the alkali metals. All three coefficients depend, in magnitude and as functions of temperature, on the shape of the Fermi surface and on the lattice spectrum. If it is assumed that the latter is identical in form for all metals in the group, the observed transport coefficients are consistent with a Fermi surface which is quite distorted in lithium, becomes nearly spherical in sodium and potassium, and is again distorted in rubidium and caesium. The argument is not sufficiently accurate to discriminate between s -like and p -like symmetry in each case, nor to decide whether the Fermi surface actually touches the zone boundary; the phonon drag effect is also very sensitive to the purity of the specimen.