The separation of Shockley partial dislocations in Si and Ge was measured for dislocations at, and near, screw orientation using the weak-beam method of electron microscopy. The separations appeared to fall into two categories. The first category had dissociations which agreed with those expected from previous measurements for dislocation orientations above 30°, and the stacking fault between the partials was intrinsic in character. The second category had dissociations which were wider than those in the first category, and the stacking fault was extrinsic in character. The stacking-fault energy of Si was deduced to be 70mJ/m2.

Dissociation of Near-Screw Dislocations in Germanium and Silicon. A.Gomez, D.J.H.Cockayne, P.B.Hirsch, V.Vitek: Philosophical Magazine, 1975, 31[1], 105-13