Electrical Conductivity of Mixed Conductors (YO_1.5)_x-(CeO₂)_y-(ZrO₂)_1-x-y

Abstract

The Y2O3-ZrO2 binary system ceramic is considered to be most developed in application to the ZrO2-based materials. A cubic fluorite structure is generally achieved, as the metal ion of the additive (Y) takes place of the Zr4+ and oxygen ion vacancies are produced in the lattice to maintain the charge balance. This leads to almost totally ionic conductivity. The introduction of changeable valued CeO2 can further improve the total electronic conductivity through the defect equilibrium reaction between tetravalent Ce4+ and trivalent Ce3+ at high temperature and reducing atmosphere. In this study, solid phase synthesis method was employed for the preparation of (YO1.5)x-(CeO2)0.08-(ZrO2)0.9-x and (YO1.5)0.05-(CeO2)y- (ZrO2)0.95-y ceramics, while four probe DC conductivity measurement method was also applied under the temperature between 300 to 800°C. The results prove that the concentration of Y3+ is the main contribution of the electrical conductivity at low temperature.