The temperature dependences of the conductivity and mobility were measured directly in samples which were undoped, or were doped with PbO or SnO2. It was found that the conductivity and mobility increased with increasing temperature. The addition of PbO increased the number of non-bridging O functional groups. Changes which were caused, to the potential energy that was experienced by mobile cations, were explained in terms of the formation of non-bridging O functional groups and/or ion association.

K.M.Shaju, S.Chandra: Solid State Ionics, 1996, 86-88[1], 453-8