In electron microscope studies of crystalline solids there is a broad
class of very small objects which are imaged primarily by strain contrast.
Typical examples include: dislocation loops, precipitates, stacking fault
tetrahedra and voids. Such objects are very difficult to identify and
measure because of the sensitivity of their image to a host of variables and
a similarity in their images. A number of attempts have been made to publish
contrast rules to help the microscopist sort out certain subclasses of such
defects. For example, Ashby and Brown (1963) described semi-quantitative
rules to understand small precipitates. Eyre et al. (1979) published a
catalog of images for BCC dislocation loops. Katerbau (1976) described an
analytical expression to help understand contrast from small defects. There
are other publications as well.
FORMATION OF CONTACT BETWEEN SQUEEZED CRYSTALLINE SOLIDS
