Samples of La1-xSrxScO3-α (x = 0.05 to 0.5) oxides with a high ionic conductivity were synthesized by using the solid phase method. The electrical conductivity increased as the value of x was increased. When x was greater than 0.35, the compound underwent a phase transition at 1073K. The addition of 2mol%Al to the Sc site was very effective in suppressing the transition. However, the conductivity of La0.65Sr0.35Sc0.98Al0.02O3 was lower than that of La0.675Sr0.325ScO3. The La0.675Sr0.325ScO3 was an unstable solid which maintained a high ionic conductivity even when effectively stabilized by 1mol%Al doping at the Sc site. No n-type conduction in La0.675Sr0.325Sc0.99Al0.01O3 was observed under low O partial pressures.

Electrical Conductivity of Al-Doped La1-xSrxScO3 Perovskite-Type Oxides as Electrolyte Materials for Low-Temperature SOFC. H.Kato, T.Kudo, H.Naito, H.Yugami: Solid State Ionics, 2003, 159[3-4], 217-22