Thermodynamic tetragonal phase stability in sol-gel derived nanodomains of pure zirconia

Nanocrystalline (15-30 nm) and submicron-sized (500-600 nm) zirconia (ZrO2) particles are synthesized using the sol-gel technique. The metastable tetragonal phase is stabilized at room temperature within pure ZrO2 nanodomains of size 15-45 nm having nonspherical morphology. Using thermodynamic analysis, it is revealed that the critical nanosize for tetragonal phase stabilization, at room temperature, may vary depending on the contribution from the surface, interfacial, and strain energies, which determine the size and the shape of the tetragonal nanodomains.