On the Defect Structure of ZrO[sub 2] and HfO[sub 2]

The defect structure of and has been studied through measurements of electrical conductivity as a function of oxygen pressure. The electrical conductivity exhibits an unusual and complex oxygen pressure dependence, and to explain the results it has been proposed that these oxides are ionic conductors and that a coupled transport of oxygen vacancies and interstitials is faster than an independent transport of these defects. Thermogravimetric measurements on suggest that the nonstoichiometry of this oxide is more than a factor of ten smaller than that observed by Aronson.