Effect of microstructure on the electron-phonon interaction in the disordered metalsPd60Ag40

Abstract

Using the weak-localization method, we have measured the electron-phonon scattering times ${\ensuremath{\tau}}_{\mathrm{ep}}$ in ${\mathrm{Pd}}_{60}{\mathrm{Ag}}_{40}$ thick films prepared by dc- and rf-sputtering deposition techniques. In both series of samples, we find an anomalous $1/{\ensuremath{\tau}}_{\mathrm{ep}}\ensuremath{\propto}{T}^{2}l$ temperature and disorder dependence, where l is the electron elastic mean free path. This anomalous behavior cannot be explained in terms of the current concepts for the electron-phonon interaction in impure conductors. Our result also reveals that the strength of the electron-phonon coupling is much stronger in the dc- than rf-sputtered films, suggesting that the electron-phonon interaction is not only sensitive to the total level of disorder, but is also sensitive to the microscopic quality of the disorder.