The instability and resulting phase transition of cubic zirconia

The instability of cubic zirconia(c-ZrO2) and the microstructure evolution associated with the cubic-to-tetragonal phase transition are discussed from experimental data together with theoretical approach using computer simulation. It was found that the electrical repulsive interaction between neighboring oxygen ions is a parameter to describe the instability of c-ZrO2. Assuming that this phase transition is of a second-order type, very unique microstructures such as the domain structure and the modulated structure, can be simulated by computer. The results are consistent with the microstructures developed by the diffusionless c–t phase transition and also the diffusional phase separation, which were experimentally observed in ZrO2-Y2O3 and the other binary systems containing cubic stabilizing oxides. It is also predicted from the simulation that cations such as yttrium ions tend to be segregated in antiphase domain boundaries (APBs) during annealing in a single t-ZrO2 field. The segregation of yttrium ions in APBs of a single t-ZrO2 was experimentally detected in the system ZrO2-Y2O3-TiO2.