Transport Properties of Pure Metals at High Temperatures: I. Copper

Abstract

This paper is the hrst of a series reporting our investigations into the hightemperature properties of the monovalent metals. I t contains a description of the nlethods used in these investigations, and the results of measurements of the transport properties of pure copper, over the temperature range 300-1 250 'I<. These results are compared \\.it11 solue previously published work, and also with standard theoretical esprcssions applicable to the monovalent metals.'Issued as N.R.C. No. 9'760. *The non~enclature on this point is somewhat confused. The ratio Ap/T, where A is the measured thermal conductivity, is son~etimes called the "Lorenz function" or even the "Lorenz number". \I:e prefer to call it the \Viedemann-Franz ratio, and reserve the term Lorenz nuiuber for thc Sommerfeld value, Lo = ?r2k2/3e2, and Lorenz function for the (theoretical) ratio X,p/T, \\.here A, is the electronic part of A.

Thermal conductivity of ten selected binary alloy systems

“…The values calculated from eqs. (12) and (35) are in good agreement with these measurements at those temperatures for which It was possible to calculate the lattice component. The investigation by Fletcher and Greig 1841 of the thermal conductivity of palladiumsilver alloys revealed that the strong electron-phonon interaction in palladium-rich alloys suppresses the low temperature lattice thermal conductivity, causing its maximum to occur at much higher temperatures than in silver-rich alloys.…”

“…Such a deviation has been observed in Cu [12,13]. In transition metals normal electronelectron interactions between s and d band electrons contribute to the electrical resistivity as well as to the thermal resistivity; these processes are very strong [14,151 and are generally thought to be responsible for the T2 temperature dependence of the electrical resistivity observed in these metals at low temperatures.…”

“…Equation (12) While a considerable amount of effort has been concentrated on the study of deviations from Matthieesen! a rule, far less attention has been given to their relation to the deviations from ite thermal analog 11, 17,181.…”

“…(12). Lattice thermal conductivity values were derived as the differences of the experimental k data and the calculated ke values.…”

“…The electronic component was calculated from eq. (12). However, these calculations were limited to temperatures below 400 K, since no reliable electrical resistivity data were available at higher temperatures.…”