Quadratic temperature dependence of the electron-phonon scattering rate in disordered metals

We have measured the electron-phonon scattering rates 1/tau(ep) from a weak-localization study of a series of high-resistivity tin-doped Ti73Al27 alloys. The resistivities of these alloys are essentially the same and are so high that the electron elastic mean free path I approaches the interatomic spacing, resulting in a very small value of q(ph) l approximate to 0.0056 T (q(ph) is the wave number of the thermal phonons, and T is the temperature). Based on as many as about 60 magnetoresistivity measurements between 2 and 22 K, we are able to determine the dependence of 1/tau(ep) on T to within a great degree of accuracy and find that 1/tau(ep) varies essentially with T-2 in the dirty limit (q(ph) l much less than 1). This observation is not understood in terms of the current theoretical concept of electron-phonon interaction in disordered metals. [S0163-1829(99)05030-4].