Synthesis and characterization of La 0.85Sr 0.15Ga 0.85Mg 0.15O 3− δ electrolyte by steric entrapment synthesis method

Abstract

Strontium and magnesium doped lanthanum gallate La 0.85Sr 0.15Ga 0.85Mg 0.15O 3− δ (LSGM) oxygen ionic conducting ceramics were prepared by a steric entrapment synthesis (SES) method, which is a polymeric precursor synthesis method by using polyvinyl alcohol in aqueous solution. The perovskite LSGM phase formed essentially at a calcination temperature of 900 °C. Pure and single perovskite LSGM phase with high relative density of 97.1% was obtained after sintering at 1450 °C, while the relative density of the LSGM sample sintered at the same temperature by solid state reaction (SSR) method was 80.6% in present experiment. Comparing with SSR synthesis method, the sintering temperature by SES can be reduced at least 100 °C. Impedance spectra revealed that the grain-boundary resistivity of LSGM synthesized by SES was smaller than that by SSR method, and the conductivities of the samples by SES were higher than those by SSR method at all measuring temperatures.