The occurrence of stacking fault formation during the preparation of -phase material was investigated. It was noted that samples which were formed via solid-gas reaction had a whisker morphology with a high stacking fault density, whereas samples which were formed via solid-solid reaction were spherical particles with a low stacking fault density. It was found that the average size of the particles decreased with decreasing reaction temperature and time. The stacking fault content, as measured by means of X-ray diffraction, was higher than the true value. This was attributed to a size effect. The stacking fault density increased with increasing heating rate, due to an increased reaction rate.

W.S.Seo, K.Koumoto: Journal of the American Ceramic Society, 1996, 79[7], 1777-82