Inelastic Scattering of Conduction Electrons: Evidence for a New Mechanism?

Measurements of the inelastic scattering time, ${\tau }_{\mathrm{in}}$, for diffusive electrons in three-dimensional indium-oxide films are reported. Two distinct regimes for the behavior of ${\tau }_{\mathrm{in}}$ as a function of temperature and disorder can be recognized: For small values of $K_{\mathrm{F}}l$, Coulomb interactions give the dominant contribution to ${\tau }_{\mathrm{in}}$. As $K_{\mathrm{F}}l$ increases, a distinctly different scattering mechanism takes over.