The equilibrium of dissociated dislocations was considered in terms of intrinsic properties such as the ideal stacking fault energy and stacking fault strain. The former was defined to be the energy per unit area of an infinitely extended stacking fault in an ideal infinite crystal. The effective stacking fault energy was defined to be the energy per unit area of a terminated stacking fault. The latter was associated with a strain field which was modelled here in terms of conventional or Somigliana dislocations. It was found that the effective stacking fault energy appreciably over-estimated the ideal stacking fault energy if this was low and the stacking fault strain was high.

P.Müllner, P.J.Ferreira: Philosophical Magazine Letters, 1996, 73[6], 289-97