Structural investigation of tetragonally stabilized ZrO2 in α-Al2O3-ZrO2 composites

A detailed structural analysis and phase-stabilization study of tetragonal (t-) ZrO2 in alpha-Al2O3-ZrO2 composites has been performed via Rietveld refinement of X-ray powder diffraction data and Fourier transform infrared ( FTIR) spectroscopy. It is observed that the tetragonal distortion (delta) of t- ZrO2 in the composites is similar to that of pure t- ZrO2. Although the average Zr - O bond distances are similar to those of other cation-doped zirconias, the X-ray and FTIR study gave no indication of Al2O3 - ZrO2 solid-solution formation. It is concluded that other factors, such as oxygen vacancies, play a significant role in the stabilization process. It may be argued that size-stabilized t-ZrO2 is actually an oxygen-deficient form.