An X–Ray Criterion for Distinguishing between Lattice Curvature and Fragmentation

Abstract

ASTERISM in Laue photographs and the arc–shaped smears in monochromatic X–ray photographs show that, in plastically deformed crystals, regions of different orientation are present. This may be due either to local curvatures of the lattice^1,2, or to its disintegration into a mosaic of small fragments the orientations of which are independent of those of their neighbours^3,4. It has been considered that X–ray methods could only reveal the existence of regions of different orientation, but could not give information as to how these regions were joined together, and thus could not tell which of the two alternatives, curvature or fragmentation, was present.