Extended solid solutions of the form, (NaFeO2)1-x(SiO2)x, where x was between 0 and 0.327, were prepared. When x was between 0 and 0.14, the solid solution had the β-NaFeO2 structure. The structure for x-values of between 0.12 and 0.25 could be derived from the latter structure by doubling 2 of the 3 orthorhombic axes. At x-values of between 0.27 and 0.327, the structure was cubic. It was shown that solid solutions with x-values of between 0.1 and 0.2 were reasonably good Na+ ionic conductors at 600K (table 106).

A.Rulmont, P.Tarte, J.M.Winand, M.Almou: Journal of Solid State Chemistry, 1992, 97[1], 156-62

Table 106

Ionic Conduction in (NaFeO2)1-x(SiO2)x Solid Solutions