Defect structure and processes in a 1-D periodic interface

The majority of experimental observations and atomistic simulations of interfaces are concerned with two dimensionally periodic structures. However, most interfaces in engineering materials have a more general character, and it is important to study these. The present work describes computer simulation of a one-dimensionally periodic interface and represents the first step towards study of more general interfaces. The particular interface investigated is a [1-210]/90 degrees tilt boundary in alpha-Ti (h.c.p.), where the boundary plane is (10-10) in one crystal and (0001) in the other. This configuration exhibits periodicity along the tilt axis but is incommensurate perpendicular to this. A many-body potential of the Finnis-Sinclair type has been used in the simulation. The minimum energy structure has been determined and the nature of defects investigated. In contrast to periodic interfaces, the defects are not localised in some cases.