Phase Transformation Kinetics in the System Bismuth Oxide‐Zirconia

The effect of ZrO2 addition on the phase transformation of Bi2O3 was studied with powder X‐ray diffraction and differential thermal analysis. Samples containing higher than a few mole percent ZrO2 were obtained as the metastable β phase (tetragonal) at room temperature when they were cooled at 20°C/min from 800°C where the δ phase (fcc) is stable. When the same samples were cooled at the same rate from 1000°C, which is above the solidus, they formed the stable α phase (monoclinic) at room temperature. Evidence for the relatively higher solubility of ZrO2 in the α phase is discussed to explain this observation. Copyright © 1990, Wiley Blackwell. All rights reserved