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Slowly cooled nitrided zirconia samples were investigated and characterized by means of transmission electron microscopy (TEM). Besides the well‐known different modifications of ZrO2 some ZrO2‐rich oxynitride phases could be further found, called β‐type phases. An overview regarding the formation of such different structural modifications could be gained, supported by previously performed measurements using powder X‐ray diffractometry (XRD). Similar to fast cooled nitrided zirconia samples Zr(N,O), the slowly cooled ones also contain different kinds of ZrO2 precipitates, which can be obviously emphasized by using the methods of diffraction contrast. A super cell was successively built, derived from the unit cells of the β and β′ phase, in order to explain the structure of the observed modulated β″ phase. Agreements from the comparisons between experimental high resolution images and the simulated ones of such modulated structures confirm the suggested starting points. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

A thorough comparison between the slowly and fast cooled ß"-type oxynitrides of zirconium has been carried out by means of transmission electron microscopy. This work aims at detecting and analyzing the so-called "modulated" β'' phase, which has been involved in the introduction of ordered anion vacancies through nitridation of zirconia. The gained information from the occurrence of such a modulated phase and the manner, in what it appears, do support the suggested structure model, which had been developed in early works in order to get a better understanding of the typical phase transitions in zirconium oxynitrides.*

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