Structure of a coincidence and near-coincidence tilt boundary in gold

The structure of tilt grain boundaries formed by a rotation of 60°and 30°about a 〈111〉 axis has been examined by transmission electron microscopy. In specimens containing 30°boundaries, low-angle dislocation arrays with a tilt angle of 2.2°are commonly observed. This is attributed to the presence of a coincidence site lattice relation at 27.8°. © 1972 The American Institute of Physics.