Domain structures in tetragonal zirconia, which were formed by the diffusionless cubic-tetragonal transformation, were studied in ZrO2-3Y2O3-12mol%TiO2 samples which exhibited a wide single tetragonal zirconia field. During annealing in the single-phase field, domain boundaries with antiphase boundary-like contrast tended to become faceted; with a habit plane that was close to one of the {111} planes. Transmission electron microscopy energy-dispersive spectroscopic analysis showed that Y ions segregated to the domain boundaries. Since the domain boundaries had a cubic structure, they were stabilized by the segregation of Y ions; which were known to stabilize cubic zirconia.

H.Ogawa, A.Yasuda, N.Shibata, Y.Ikuhara, T.Sakuma: Philosophical Magazine Letters, 1998, 77[4], 199-203