Grain-Boundary, Glassy-Phase Identification and Possible Artifacts

Abstract

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 view point and compared to experimental results obtained for alumina.

Secondary dislocations in [011] tilt boundaries in germanium

“…The 'quality' of the lattice-fringe images also suffered from preferential milling of the boundary regions, which further complicates the interpretation. This preferential thinning is a common problem in HREM image interpretation and has recently been discussed by Kouh, Carter, Morrissey, Angelini and Bentley (1986) and by Simpson, Carter, Sklad and Bentley (1986). The present analysis will therefore be restricted to the determination of the Burgers vectors of secondary dislocations which are identified by the fact that they cause irregularities in the spacing of the primary dislocations.…”