Published online by Cambridge University Press: 15 February 2011
Mn2O3 was added to YSZ (8 mol% yttria- doped zirconia) either to form solid solution or two-phase (Mn2O3 and Mn2O3 doped-YSZ) mixed-conducting oxide. The electrical conductivity was measured between 600 and 1000°C in air using 4-probe d.c. method in a wide composition range to determine composition-dependent conductivity. Up to 12 mol% MnO1.5 addition, the conductivity decreases and the activation energy increases. With further increase of MnO1.5 content, the conductivity of composite begins to increase slowly and then increases rapidly after 30 mol% due to the interconnected, conductive Mn2O3 particles. Above 35 Mol% MnO1.5 content, the activation energy is nearly the same as that of Mn2O3. Hysteresis behavior shown in the conductivity of composite also provides the evidence of percolation by MnO1.5.