OBSERVATION OF A LINEAR MEAN-FREE-PATH DEPENDENCE OF THE ELECTRON-PHONON SCATTERING RATE IN THICK AUPD FILMS

We have fabricated several thick AuPd films with residual resistivitie s rho(0) varying from 69 to 229 mu Omega cm. With this wide range of e xperimentally accessible rho(0), we are able to study the dependence o f the electron-phonon scattering time tau(e-ph) on the electron elasti c mean free path l. We have measured the magnetoresistivities of these films and compared our results with weak-localization theory to extra ct tau(e-ph) Our results indicate a temperature and mean-free-path beh avior of 1/tau(e-ph) similar to lT(2). This observation is in disagree ment with current theoretical understanding of electron-phonon interac tion in disordered conductors.