A new defect at the intersection between grain boundaries and surfaces in Au was identified by using atomic resolution transmission electron microscopy. At the junction line of 90° <110> tilt grain boundaries of (110)-(001) orientation with the free surface, a small segment of the grain boundary, about 1nm in length, dissociated into a triangular region with a chevron-like stacking disorder and a distorted hexagonal close-packed structure. The structure and stability of these defects was confirmed by atomistic simulations, and the relationship to the 1-dimensional incommensurate structure of the grain boundary was pointed out.

Chevron Defect at the Intersection of Grain Boundaries with Free Surfaces in Au. T.Radetic, F.Lançon, U.Dahmen: Physical Review Letters, 2002, 89[8], 085502 (4pp)