Microscopic Explanation of the Non-Arrhenius Conductivity in Glassy Fast Ionic Conductors

To explore the origin of the recently discovered non-Arrhenius behavior of the dc conductivity in glassy fast ionic conductors at high temperatures, we investigate by Monte Carlo simulations the transport of charged particles in an energetically disordered structure. We show that the combined effect of Coulomb interaction and disorder can account for the experimental findings. Our results suggest that glassy superionic conductors can be optimized by lowering the strength of the energetic disorder but that the ionic interaction effects set an upper bound for the conductivity at high temperatures.