Temperature and Mean-Free-Path Dependences of Electron-Phonon Scattering Times in Disordered Metals

We have successfully fabricated a series of thick AuPd films and a series of Ti_1-xAl_x alloys which have wide ranges of residual resistivities ρ_0. With a wide range of experimentally accessible ρ₀ for each series of samples, we are able to study the dependence of the electron-phonon scattering time τ_ep on the electron mean free path l. We have measured the magnetoresistivities of our samples at liquid-helium temperatures and compared our results with 3D weak-localization theory to extract τ_ep. Our results indicate a temperature and mean-free-path behavior of 1/τ_ep ~ l T^2 in thick AuPd films, and 1/τ_ep ~ T^2/l in Ti_1-xAl_x alloys. Our results are in disagreement with current theoretical understanding of electron-phonon interaction in disordered conductors.