Surface segregation and effect of mechanical stress on Sb-stabilised tetragonal zirconia

Compact pressure effects on Sb-doped tetragonal zirconia have been monitored using XRD, Raman and FTIR spectroscopies. A martensitic tetragonal-->monoclinic transformation, driven by compact pressure, has been observed upon pelletisation of stabilised samples. By contrast, no monoclinic phase has been observed on amorphous powders upon pelletisation and firing. Sb surface segregation has been observed upon firing of pellets. The phenomenon has been quantitised by angle resolved XPS using the recent Gries algorithms to evaluate the Zr 3d photoelectron inelastic mean free path in ZrO2 which, in turn, compares well with previous experimental data. Surface Sb segregation occurs over a depth range and involves many ionic planes. An experimental estimate of the Sb segregation enthalpy has been evaluated.