Zirconium oxide exists in monoclinic crystal at room temperature, and will be converted into square crystal phase as temperature rises to 1,170°C and then converted into cubic crystal phase as temperature rises to 2,370°C, while cubic crystal phase will be dissolved into liquid phase at 2,680°C, the conversion from square crystal into monoclinic crystal is a martensitic transformation, and such phase conversion may produce 3 – 5% volume change, resulting micro cracks. 

Effective dopants include Yttrium oxide (Y2O3), Magnesium oxide (MgO),  Calcium oxide (CaO) which stabilizing agents to make sure that zirconium oxide can maintain the high-temperature stable phase, that is cubic crystal phase, which is called the stabilized zirconium oxide; if yttrium oxide phase stabilizer is added to keep partial square crystal phase, it can be called partially stabilized zirconium oxide.


Stabilized zirconium oxide is used in all kinds of ceramic, electric ceramic, biological ceramic(Dental), optical fiber connectors, advance mechanical parts, grinding media, oxygen sensor, solid oxide fuel cell etc.