1 Department of Physics, Technical University of Denmark2 Risø National Laboratory for Sustainable Energy, Technical University of Denmark3 Department of Wind Energy, Technical University of Denmark4 Materials science and characterization, Department of Wind Energy, Technical University of Denmark5 Department of Energy Conversion and Storage, Technical University of Denmark6 unknown
Large scale atomistic simulations are used to investigate the properties of screw dislocation dipoles in copper. Spontaneous annihilation is observed for dipole heights less than 1 nm. Equilibrated dipoles of heights larger than 1 nm adopt a skew configuration due to the elastic anisotropy of Cu. The equilibrium splitting width of the screw dislocations decreases with decreasing dipole height, as expected from elasticity theory. The energy barriers, and corresponding transition states for annihilation of stable dipoles are determined for straight and for flexible dislocations for dipole heights up to 5.2 nm. In both cases the annihilation is initiated by cross-slip of one of the dislocations. For straight dislocations the activation energy shows a linear dependence on the inverse dipole height, and for flexible dislocations the dependence is roughly linear for the dipoles investigated.
Philosophical Magazine. A. Physics of Condensed Matter. Defects and Mechanical Properties, 2000, Vol 80, Issue 5, p. 1273-1290