Phonon thermal conductivity limited by electron scattering in amorphous ${\mathrm{Zr}}_{70}$${\mathrm{Cu}}_{30}$

The low-temperature thermal conductivity of amorphous ${\mathrm{Zr}}_{70}$${\mathrm{Cu}}_{30}$ is investigated. The lattice thermal conductivity as limited by electrons in the superconducting state has been obtained at temperatures close to $T_c$. This has allowed for the first time the verification of the temperature dependence of the phonon conductivity as predicted by Bardeen, Rickayzen, and Tewordt. The analysis of the data in the normal and superconducting state shows that Matthiessen's rule can be used in amorphous metals to separate the different scattering processes.