Computer simulations were made of a 1-dimensionally periodic interface, as a first step towards treating more general interfaces. The interface investigated was a [1¯2▪0]/90º tilt boundary, where the boundary plane was (10▪0) in one crystal and (00▪1) in the other. This configuration exhibited a periodicity along the tilt axis, but was incommensurate in directions perpendicular to this. A many-body potential of the Finnis-Sinclair type was used in the simulation. The structure of the boundary did not resemble a misfitted hetero-interface with an array of localized dislocations, but instead exhibited ribbons of screw dipoles that were arranged parallel to the tilt axis with the pseudo-periodicity of the interface perpendicular to the tilt axis. The boundary could not sustain moderate shear stresses perpendicular to the tilt axis, with the result that components of crystal dislocations that were absorbed into the boundary became delocalized. The core structures of the localized interfacial defects exhibited preferred riser configurations which resembled (10▪2) twins. This had important consequences for the movement of interfacial defects under an applied stress.

Defect Structure and Processes in a 1-D Periodic Interface. A.Serra, D.J.Bacon, R.C.Pond: Materials Science Forum, 1999, 294-296, 195-8