High-Resolution Electron Microscopy of Twist and General Grain Boundaries

High-resolution imaging of atomic structures of twist and general grain boundaries (GBs) is reported in samples prepared by a thin-film technique in which [011] and [001] oriented Au grains are epitaxially grown side by side, allowing the investigation of a wide range of GB geometries. GBs with tilt as well as twist components typically have structural modulations along the interface and often show a surprising amount of coherence between lattice planes crossing the interface. The [110], 90{degree} symmetric twist GB does not remain planar, but reconstructs into atomic-scale microfacets. {copyright} {ital 1999} {ital The American Physical Society }