(U_0.7Y_0.3)O_2+x/YSZ interface

Abstract

Complex impedance measurements were made on (U_0.7Y_0.3)O_2+x/YSZ/(U_0.7Y_0.3)O_2+x cells, both powder and dense disc electrodes being used. The depressed electrode arcs have been fitted to a circuit (proposed previously) containing frequency-dependent components. Surface roughness and the porosity of the electrode have little effect on the angle of depression of the electrode arc. Instead,it is suggested that this behaviour is caused by multipaths in the overall charge-transfer reaction in which more than one step dominates the rate process as the frequency is changed.