Non-parallel dissociation of dislocations in thin foils

The equilibrium shape of dissociated dislocations in thin foils of Cu-10 at.% Al is investigated by weak-beam electron microscopy. It is found that dislocations assume a truncated triangular shape caused principally by the reduction in line energy when Shockley partials rotate towards screw character. The effects of interaction image stresses and surface slip steps are generally small, but the former may be important in the case of spontaneous cross-slip of a dislocation at a surface.