Electron-phonon scattering and electrical conductivity of graphite intercalation compounds

Abstract We formulate a microscopic theory of electron-phonon scattering for graphite intercalation compounds and apply it to interpret the data of C 8 AsF 5 . The theory refers mainly to acceptor compounds since conduction is assumed to be purely planar. For electron-phonon scattering we consider both the phonons of the graphite layers and the modes of the charged intercalate molecules. Scattering with graphite phonons is computed from first principles within a tight binding framework. A problem of anisotropic screening has to be solved for scattering by modes of the charged intercalate molecules. We find that the crucial effect for this scattering mechanism is the pinning of the intercalate molecules due to the graphite layers. As a specific application, we compute the absolute value and temperature dependence of the conductivity of C 8 AsF 5 , obtaining good agreement with experiment. The final results of the theory can be expressed in a simple analytical form.