FREEZEOUT OF THE ELECTRICAL-RESISTIVITY IN (BEDT-TTF)(2)I-3 BELOW 20-K

We have measured the temperature (T) dependence of the resistivity rho of the beta and kappa phases of (BEDT-TTF)(2)I-3 from 300 K down to T -c (similar to 1.3 K and similar to 4 K for the beta and kappa phases, respectively). Between 100 K and 20 K, rho proportional to T-2. Below 20 K, the resistivity falls below the T-2 law. We calculate the resis tivity due to electron-electron scattering and find that this contribu tion is far too small to account for the measured resistivity, besides being inconsistent with the freezeout below 20 K. We suggest that the resistivity is due to electron-phonon scattering, described by a nove l mechanism that has been proposed for the high-T-c cuprates. We also suggest that this mechanism accounts for tbe T-2 law observed in mater ials such as TiS2, Nb-doped SrTiO3, and intercalated graphite.