Ionic and electronic conductivity of 3 mol% Fe2O3-substituted cubic yttria-stabilized ZrO2 (YSZ) and scandia-stabilized ZrO2 (ScSZ)

Scandia-stabilized zirconia (ScSZ) electrolytes exhibit the highest ionic conductivity among all ZrO2-based materials. However, a phase transition occurs around 650 °C from cubic to rhombohedral β-phase which is unique for Sc-stabilized zirconia and leads to reduced conductivity. The occurrence of this β-phase can be suppressed by co-doping ScSZ. The aims of this study are to confirm the influence of a small amount of Fe2O3 doping on both the stabilization of the cubic phase and the decrease of the sintering temperature and to investigate the influence of this co-doping on the ionic and electronic conductivity of ScSZ. Therefore (ZrO2)0.90–(Sc2O3)0.07–(Fe2O3)0.03 powder has been prepared by precipitation in aqueous solution and sintered at 1380 °C to obtain ceramic. The electrical properties (ionic and electronic conductivities) of this ceramic are compared to the ones of Fe-doped YSZ.