RETICULOGRAPHY - A SIMPLE AND SENSITIVE TECHNIQUE FOR MAPPING MISORIENTATIONS IN SINGLE-CRYSTALS

Interposition of a fine-scale X-ray absorbing mesh between a Laue-diff racting crystal specimen and the photographic plate recording its topo graphic image splits the diffracted beam into an array of individually identifiable microbeam elements. Direction differences between the mi crobeams in the array, which are twice the orientation differences bet ween the crystal elements reflecting them, are measured by recording t he array at two or more mesh-to-photoplate distances. Maps of misorien tation vectors over the crystal lattice planes under examination can b e derived from these array images by visual or digital electronic metr ological procedures. Applications to two specimens widely different in diffracting properties are described. Angular size of the X-ray sourc e is the principal instrumental factor setting misorientation detectio n limits, and was less than 1 are second in this work.