Nature and Thermal Evolution of Amorphous Hvdrated Zirconium Oxide

The thermal behavior of amorphous hydrated zirconium oxide and its coprecipitates with other oxides was studied. Solid solution with a limit of solubility seems to exist in the amorphous coprecipitates. A relation with the high‐temperature solid solution was established. The structure of the amorphous zirconia was studied by X‐ray and neutron diffraction; a thin plate model related to the structure of tetragonal zirconia is proposed. Heating the precipitates in an oxygen‐free atmosphere produced a black nonstoichiometric oxide and stabilization of the tetragonal form.