The lattice thermal conductivity of dilute copper alloys at low temperatures

Author(s):  
G.K. White ◽  
S.B. Woods
1955 ◽  
Vol 33 (2) ◽  
pp. 58-73 ◽  
Author(s):  
Guy K. White ◽  
S. B. Woods

An apparatus for measuring the thermal and electrical conductivities of solids at temperatures between 2° and 300°K. is described. Results are presented of measurements of some dilute copper alloys, beryllium, bismuth, and germanium. Where possible the lattice thermal conductivity has been deduced, directly or indirectly from the measurements, and its magnitude and variation with temperature are discussed with relation to theory.


The thermal and electrical conductivities of silver and copper alloys with high electrical resistivities were studied in the temperature range from 0.3 to 4 °K. The lattice thermal conductivity results were interpreted in terms of Pippard’s semi-classical theory of the electron-phonon interaction and good qualitative agreement between this theory and the measurements was obtained for the temperature range from 1 to 4 °K. Below 1 °K the thermal conductivity of most samples decreased much more rapidly than one would have expected if the phonon mean free path were limited by the electron-phonon interaction only. Other phonon scattering mechanisms were therefore postulated and the effects of phonon scattering from dislocations was studied both theoretically and experimentally. The increase in thermal resistance below 1 °K of most alloys was more rapid than the increase obtained theoretically for phonon-dislocation and phonon-boundary scattering. The thermal conductivity of a copper sample with a resistance ratio of about 85 was found to be anomalous below 1 °K as well, suggesting that both the phonons and the conduction electrons could contribute to the effect in the alloys.


Sign in / Sign up

Export Citation Format

Share Document