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.