The observation of various grain boundary atomic structures in Au by high-resolution electron microscopy

A number of grain boudary structures prepared from evaporated Au thin films have been investigated using very high-resolution electron microscopy. Particular emphasis has been placed on analyzing [110] tilt boundaries with both low- and high-angle misorientations. Observations of the atomic positions at dislocation cores and close-packed polyhedral shapes at the interface have been made. Symmetric boundaries have been observed as well as interfacial regions where the grain orientations deviate from perfect coincidence and hence the boundary structure exhibits perturbations to the regular polyhedron stacking. The special case of "plane coalescence" has also been observed, as well as the boundary splitting near a hole. The fabrication and observation of a generalized boundary, which cannot be classified as a tilt structure, will also be demonstrated.