Direct Observation of Misfit Dislocation Glide on Surfaces

Abstract

Using scanning tunneling microscopy we have observed thermally induced dislocation glide in monolayer Cu films on Ru(0001) at room temperature. The motion is governed by a Peierls barrier that depends on the detailed structure of the dislocations, in particular upon whether the threading dislocations that terminate them are dissociated or not. Calculations based on the Frenkel-Kontorova model reproduce the threading dislocation structure and provide estimates of the Peierls barrier and dislocation stiffness which are consistent with experiment.

Fast scanning tunnelling microscopy as a tool to understand changes on metal surfaces: from nanostructures to single atoms

“…The one-dimensional random walks are due to adatoms being exchanged between the core of the dislocation in the solid film and the adatom gas covering the film. In the perpendicular direction, the dislocations behave like strings under tension for small displacements from their equilibrium orientation [75]. Experimentally, a stiffness of 70 meV/a was determined at room temperature.…”

Atomic structure of screw dislocations intersecting theAu(111)surface: A combined scanning tunneling microscopy and molecular dynamics study

“…Especially the possibility to combine modern atomistic large scale simulations with STM observations ͑with down to atomic resolution at the surface͒ to provide detailed atomistic understanding of the structure and dynamics of defects, has triggered more recent investigations on naturally occurring and/or artificially introduced defects on single crystals [17][18][19][20] and thin films. 21 In the present paper, we report on the atomic structure of naturally occurring screw dislocations intersecting a single crystal Au͑111͒ surface, especially their partial-splitting width. The reason, why we chose this surface is that it exhibits the well-known herringbone reconstruction.…”

Properties of dislocation half loops inAu(100): Structure, formation energy, and diffusion barrier

“…3 Certain dislocation configurations have also been proposed to act as a pathway for the net transport of atoms parallel to the surface with extremely low activation barriers. 4,5 Dislocations are usually treated within elastic theory introducing a cutoff length for atomic positions that are too far away from equilibrium positions. Such an approach has been extremely successful.…”