Observations of Extrinsic-Intrinsic Faulting in Ag Platelets by High-Voltage Electron Microscopy

Thin, chemically grown (111) Ag platelets were deformed and studied by high-voltage electron microscopy. Dislocation networks of two kinds were found to form in the plane of the foil. The first type was the usual disclocation network of contracted and extended nodes and was usually observed in regions of light deformation. After heavier deformation a new, more complex dislocation configuration, which divides the crystal into intrinsically and extrinsically faulted regions, was observed. In some instances these dislocations form a very regular pattern. A formation mechanism for such networks is discussed in terms of present theories.