Low-Temperature Transport Properties of Commercial Metals and Alloys. IV. Reactor Grade Be, Mo, and W

Abstract

The thermal conductivity, electrical resistivity, Lorenz ratio, and thermoelectric power are given in the temperature range 4°–120°K for four reactor grade metals: beryllium with sample axis parallel to the pressing axis, beryllium with sample axis perpendicular to the pressing axis, molybdenum, and tungsten, the latter two doped with ThO2. Within the given temperature range the molybdenum and tungsten show slight maxima in thermal conductivity, the beryllium does not. The various components of the electronic and lattice thermal conductivities and resistivities are resolved. The residual electrical resistivities are, respectively, 0.64, 1.01, 0.57, and 0.16×10−6 ohm-cm. The Lorenz ratios for molybdenum and tungsten show both maxima and minima and are always below the Sommerfeld value. The ratios for the beryllium samples have broad maxima and generally are above the Sommerfeld value. The thermoelectric powers of the samples with respect to pure copper are negative for the higher temperatures and positive for the lower temperatures.