EVOLUTION OF CRYSTALLINE ZIRCONIA STRUCTURE IN HEAT-TREATED CERIA STABILIZED ZIRCONIA GELS

Transformation characteristics of CeO2 stabilized ZrO2 gels have been studied during heating in the temperature region 1273-1473 K. The nature of the major phase present changes drastically in this temperature region. The crystallite sizes of tetragonal and monoclinic ZrO2 crystallites have been calculated by x-ray line broadening. The change in the nature of the major phase observed during heat treatment seems to be related to the presence of a barrier for transformation from a metastable to a stable regime, which in turn appears to be related to the diffusion barriers of Ce4+ in ZrO2.