Diffraction by fcc Crystals with Intrinsic and Extrinsic Faults

Abstract
A model is given for diffraction by an fcc lattice which contains a randomly arranged mixture of intrinsic and extrinsic stacking faults. The expression for the distribution of intensity in reciprocal space contains, as special cases, the equations derived for intrinsic and extrinsic faulting by Paterson and by Johnson, respectively. The result and its derivation clarify a controversy which arises from Sabine's model for faulting by condensation of interstitials; some comments on this problem are given in an appendix.