It was recalled that equilibrium morphologies were frequently determined by a competition between interfacial and elastic energies, and that holes at the cores of dislocations (in materials with large Burgers vectors) were a clear example of this. That was because their existence was due only to such competition. A method for treating these phenomena was presented in terms of the morphologies for which the energy was an extremum, together with a procedure for examining the stability of the solutions. It was found that the circular core-holes around screw dislocations were stable in an isotropic material. The core holes around edge dislocations were stable, but were not circular. This was because of the symmetry of their elastic field; even in isotropic materials. Isotropic elastic energy could lead to core shapes in which the effect of surface anisotropy was exaggerated over what it would be in a Wulff plot. Most of these results were derived on the basis of a parametric form for the hole shape and an expansion of the energies which was valid for small perturbations of a circular cross-section.

Shape of Hollow Dislocation Cores: Anisotropic Surface Energy and Elastic Effects D.J.Srolovitz, N.Sridhar, J.P.Hirth, J.W.Cahn: Scripta Materialia, 1998, 39[4-5], 379-87