The atomic-scale structure of naturally occurring screw dislocations intersecting a Au(111) surface was investigated both experimentally by scanning tunneling microscopy and theoretically using molecular dynamics simulations. The step profiles of 166 dislocations were measured using scanning tunneling microscopy. Many of them exhibited non-integer step-height plateaus with different widths. Clear evidence was found for the existence of two different populations at the surface with distinct (narrowed or widened) partial-splitting widths. All findings were fully confirmed by the molecular dynamics simulations. The molecular dynamics simulations extended scanning tunneling microscopic- (that is, surface-) investigation to the sub-surface region. Due to this additional insight, the different partial-splitting widths could be explained as being the result of the interaction between partial dislocations and the surface.

Atomic Structure of Screw Dislocations Intersecting the Au(111) Surface - a Combined Scanning Tunneling Microscopy and Molecular Dynamics Study. J.Engbæk, J.Schiøtz, B.Dahl-Madsen, S.Horch: Physical Review B, 2006, 74[19], 195434 (9pp)