Samples were prepared in which Mn2O3 was added to 8mol%Y2O3-stabilized material so as to form either a solid solution or a 2-phase mixed-conduction oxide. The total electrical conductivity was measured between 600 and 1000C, in air, using the 4-probe direct-current method. The Hebb-Wagner polarization technique, and electromotive force measurement via galvanic cell, were used to determine the partial ionic and electronic conductivity. The entire composition range was divided into 3 different regions; depending upon the conduction mechanism, as distinguished by their activation energy and transference number. Within the solubility limit (12mol%MnO1.5), the total conductivity and activation energy decreased and increased, respectively, with increasing MnO1.5 content. Above the solubility limit, the total conductivity began to increase slowly due to a rapid increase in the partial hole conductivity. The total conductivity increased rapidly above 30mol%, due to interconnected conducting Mn2O3 particles.

Mixed Ionic and Electronic Conductivity of [(ZrO2)0.92Y2O3)0.08]. J.J.Kim, G.C.Chi: Solid State Ionics, 2000, 130[1-2], 157-68