Phase transformation and low temperature sintering of manganese oxide and scandia co-doped zirconia

The powders of 89 mol% ZrO2–11 mol% Sc2O3 (11ScSZ) doped with various Mn2O3 contents were prepared by a co-precipitation method combined with a SCFD (supercritical fluid drying) route. Inhibition of the cubic–rhombohedral phase transformation in both oxidation and reduction atmospheres is achieved for 11ScSZ by the addition of 2.0 mol% Mn2O3. The Mn2O3 addition can lower the sintering temperature of 11ScSZ ceramics, and the 11ScSZ–2Mn2O3 compact can be sintered to nearly full density at 850 °C. 11ScSZ–2Mn2O3 ceramic with the cubic structure sintered at 900 °C possesses the conductivity of ∼ 0.10 S cm− 1 at 800 °C, which is very promising for intermediate temperature solid oxide fuel cell (SOFC) applications.