Anomalies in the low-temperature thermal and electrical resistivities of copper

Accurate measurements of the low-temperature thermal conductivity of high-purity copper have revealed abrupt changes in the temperature dependence of the inelastic electron-phonon scattering component of the thermal resistivity ($W_V$) at about 7, 11, and 18 K. The existence of these regions and the deviation of the form of the ratio ${\rho }_n$/$W_V$ (where ${\rho }_n$ is the normal electron-phonon scattering component of the electrical resistivity) in the two lower regions from that in the two upper regions requires a reassessment of the natures and forms of the electron scattering processes in Cu.