Interstitial producing extended jogs in face-centred cubic lattices

Hirsch's theory of extended jogs in face-centred cubic lattices has been developed further. The role played by partial dislocations attached to double stacking faults (extrinsic faults) has been included in the analysis. The previous conclusion that jogs in face-centred cubic crystals can produce only vacancies and not interstitials has been modified. Both types of point defects are produced in approximately equal abundance. However, complete symmetry between vacancy and interstitial creation can occur only if the energy of a double stacking fault (extrinsic fault) is identical to that of a single stacking fault (intrinsic fault).