Zirconia ceramic lattice, structure

The crystalline form of interest in Zr-based ceramic compounds is the cubic fluorite structure based on the mineral CaF2. In this structure, consisting of interpenetrating face-centered-cubic and simple cublic arrays of cations (Zr ) and anions (O ), respectively, oxygen ion conductivity is enhanced by replacing zirconium (Zr ) ions on the cation lattice with soluble dopant cations having a valence less than 4, typically divalent (Mg, Ca ) and trivalent (Y, Yb , Sc ) cations. These dopants, which are in solid solution, are incorporated into the zirconia structure by the following types of defect reaction ... 

When elements of valence 2 or 3 are introduced into zirconia, they occupy Zr lattice sites, generating vacancies at oxygen sites. These provide zirconia with its well-known ionic conductivity, leading to its use in high temperature electrochemical cells (Subbarao and Maiti [1984], Steele [1976], Steele et al. [1981]). FSZ is mainly used for electrochemical appUcation, PSZ mainly for structural applications, while TZP is used both as a solid electrolyte and a structural ceramic. 

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