Abstract
High-resolution transmission electron microscopy has been applied to determine the atomic structure of the twin boundary in NiSi 2 . From a match with the simulated images obtained by computation, Si atoms in the type A NiSi 2 are found to bond with Si atoms in the type B NiSi 2 at the (111) twin-boundary plane, and the Ni atoms of both crystals are sevenfold coordinated. The result represents the first report of the atomic structure of the silicide twin boundary which is free from either elastic strain or misfit dislocations.