It was recalled that an ubiquitous non-Arrhenius temperature dependence of the ionic conductivity had recently been discovered in glassy fast ionic conductors when the conductivity exceeded 0.001 to 0.01S/m. This was easily explained here in terms of a coupling of the ion dynamics, without introducing any adjustable parameter. The calculation also explained why the departure from an Arrhenius temperature dependence of the direct-current conductivity had not been seen in glassy but poor ionic conductors such as alkali oxide glasses. That is, conductivities of the order of 0.01S/cm could not be attained therein at temperatures below the glass transition.

K.L.Ngai, A.K.Rizos: Physical Review Letters, 1996, 76[8], 1296-9