The effect of synthesis and thermal treatment on phase composition and ionic conductivity of Na-doped SrSiO3

Highest conductivity and degradation rate was obtained when synthesis was carried out in acetone with single calcination step at 850 °C, due to the crystallization of Na2Si2O5 from glass. Double calcination limited conductivity but increased its thermal stability. When ethanol was used for powder mixing and double calcination was applied, the material exhibited higher conductivity after long term ageing at 650 °C, also thanks to its low activation energy, without appreciable crystallization of other silicates.