THERMAL CONDUCTIVITY AND ELECTRICAL RESISTIVITY OF HIGH-PURITY COPPER FROM 78 TO 400 °K

Abstract

A guarded-axial heat-flow technique for accurately measuring thermal conductivity, electrical resistivity, and Seebeck coefficient from 78 to 400 °K on small rod samples is described in detail. Results on a 99.999% pure polycrystalline copper specimen (ρ273.16°K/ρ4.2°K = 9.0 × 102) are compared with the results of previous investigators.The behavior of the electrical resistivity and the thermal conductivity is discussed in terms of existing theoretical equations. Although copper is a relatively simple monovalent metal, little agreement between the experimental thermal conductivity results and theory was found. The behavior of the experimental electrical resistivity from 100 to 1 200 °K was explained in terms of an approximation to the Bloch-Grüneisen equation.