Precision measurements of the thermal conductivity, electrical resistivity, and Seebeck coefficient from 80 to 400 K and their application to pure molybdenum

Abstract

A longitudinal heat-flow technique for precise measurement of thermal conductivity, electrical resistivity, and Seebeck coefficient over the temperature range from 80 to 400 K is described. The basis of the technique is the use of a calibrated platinum resistance thermometer to provide in situ calibrations of specimen thermocouples. The total determinate errors at 273 K are ± 0.23% for electrical resistivity, ± 0.49% for thermal conductivity, and ± 0.07 μV/K for the Seebeck coefficient when Pt wire is used as the reference. Experimental results on two high-purity molybdenum specimens with cross-sectional areas differing by a factor of four are presented to demonstrate the system precision and low level of indeterminate erros.