The O partial pressure dependence of the electrical conductivity of (ZrO2-3mol%Y2O3)1-x (MnOy)x, where x was equal to 0, 0.030, 0.052 or 0.076, was measured at temperatures ranging from 1273 to 1373K, under O partial pressures of between 105 and 10-5Pa. It was found that the conductivity increased with decreasing pressure and that the conductivity was constant below 10-5Pa. The conductivity decreased considerably with the dissolution of only 3mol% of MnOy, but it increased gradually at above 5.2mol%MnOy. The conductivity was thought to be equal to the ionic conductivity due to O ions. A defect-structure model was proposed, and the apparent mobility of the O ion was calculated under the assumption that the valence state of the Mn ions was +3 and +2 at O partial pressures of 105 and 10-13Pa, respectively.

Electrical Conductivity and Defect Structure of Manganese Oxide-Doped Yttria-Stabilized Zirconia. T.Kawashima: Materials Transactions, 1998, 39[11], 1115-20