The dissociation, into two Shockley partials, of a dislocation in the {111} plane of a face-centered cubic crystal was studied within the framework of the generalized Peierls model. The interplanar atomic misfit energy (γ-surface) was represented by a two-dimensional Fourier series in which the stacking fault energy and the maximum stacking energy could be varied independently. Whereas, for Volterra dislocations, the separation of the Shockley partials depended only upon the stacking fault energy it was found that, in the more general treatment, the equilibrium separation also depended upon the maximum stacking energy. Previous experimental deductions of stacking fault energy from transmission electron microscopic observations therefore had to be re-evaluated. The energy which was required in order to recombine the two Shockley partials also depended upon the value of the maximum stacking energy. Agreement with the dissociation energy for a Volterra dislocation in the screw orientation could be obtained only when the recombination radius was chosen to be 0.15b.

The Dissociation Energy of Extended Dislocations in FCC Lattices. G.Schoeck: Philosophical Magazine A, 1999, 79[5], 1207-15