Secondary Grain Boundary Dislocation Structures in Gold and Silver (001) Twist Boundaries Revisited

摘要

A search was made for the presence of localized secondary grain boundary dislocations (SGBD's) in selected (001) twist boundaries in gold and silver using transmission electron microscopy. Screw SGBD networks were detected in near- sigma 5, - sigma 13, - sigma 17, - sigma 25, and - sigma 29 boundaries in gold and in near- sigma 5 boundaries in silver. The sigma 25 and sigma 29 networks were observed for the first time and extend the range of SGBD structures observed in (001) twist boundaries in gold beyond that found in earlier work (Schober and Balluffi, 1970, Philos. Mag., 21, 109). The observation of sigma 5 SGBD's in silver contradicts the claim (Pareja, 1980, Phys. Stat. Sol. (a), 62, 305) that these SGBD's are delocalized in this metal. Extensive tests were carried out to verify that all of the observed SGBD images were indeed due to localized dislocations and were not Moire fringe patterns. (ERA citation 11:054133)