Metastability of Tetragonal Zirconia Powders

Abstract

The formation of metastable t ‐ZrO 2 by thermal treatment was studied in a systematic way on two different samples: a gel (G) and zirconyl acetate (A). The results show that initially nucle‐ation of t ‐ZrO 2 is favored by creation of anionic vacancies with trapped electrons. At higher temperatures the electronic defects disappear, the crystallites grow, and the m ‐phase can nucleate. This evolution is observed perfectly on sample A because of its special morphological characteristics.