GRAIN-BOUNDARY, GLASSY-PHASE IDENTIFICATION AND POSSIBLE ARTIFACTS.

Specimen artifacts such as grain boundary grooving, surface damage of the specimen, and Si contamination are shown experimentally to arise from the ion milling used in the preparation of transmission electron microscopy specimens. These artifacts in polycrystalline, ceramic specimens can cause clean grain boundaries to appear to contain a glassy phase when the dark-field diffuse scattering technique, the Fresnel fringe technique, and analytical electron microscopy (energy dispersive spectroscopy) are used to identify glassy phases at a grain boundary. The ambiguity in interpereting each of these techniques due to the ion milling artifacts will be discussed from a theoretical viewpoint and compared to experimental results obtained for alumina.