The ionic conductivity of the mixed-ion system was calculated by using the path probability method and a 2-dimensional honeycomb lattice model which resulted from the weak interaction between 2 different ions. The 23Na magic-angle spinning nuclear magnetic resonance spectra revealed a second-order quadrupole interaction with the electric field gradient. It was concluded that the mixture of 2 ions, in a material having a 3-dimensional diffusion path, led to a shallow conductivity minimum due to the ordered distribution of Ag and Na ions.

Mixed Ion Effects in Na/Ag-NaZr2(PO4)3. N.Inoue, E.Nagahama, K.Oiwa, T.Hayashi: Ionics, 1999, 5[1-2], 140-3