The intrinsic and extrinsic stacking-fault energies of silicon were determined from images of double ribbons obtained using the weak–beam method of electron microscopy. The ribbons occurred in distorted regions of small–angle twist boundaries on {111} planes prepared by welding. The intrinsic stacking-fault energy was 69mJ/m2 and extrinsic value was 60mJ/m2; a ratio of 1.15. the intrinsic value was however also deduced from relatively isolated screw dislocations in the boundary and isolated edge dislocation in the bulk, both yielding a value of 60mJ/m2. The results were compared with values obtained from isolated dislocations in the screw and edge orientation within the same sample, which were found to be consistently lower than the values obtained from double ribbons.

Direct TEM Determination of Intrinsic and Extrinsic Stacking Fault Energies of Silicon. H.Föll, C.B.Carter: Philosophical Magazine A, 1979, 40[4], 497-510