Kinetic demixing in yttria-doped zirconia part II - theoretical analysis

This paper presents a formal analysis of the transport processes in yttria-doped zirconia under a temperature gradient. Due to the simultaneous diffusion and drift of the species when the material is exposed to a thermodynamical potential gradient, a kinetic demixing process appears on the cationic sublattice if the diffusion coefficients of the cations are different. Experimental results obtained with yttria-doped zirconia are discussed on the basis of this analysis. They confirm that kinetic demixing processes during cooling must be taken into account in the interpretation of the grain boundary conductivity of doped zirconia. Paper presented at the 7th Euroconference on Ionics, Calcatoggio, Corsica, France, Oct. 1–7, 2000.