Bragg-case synchrotron double-crystal images of stacking faults were studied in synthetic crystals. Topographs which were obtained from the tail of the rocking curves revealed well-defined interference fringes that arose from the stacking faults. This was suggested to be the first time that such an observation had been made in the Bragg diffraction geometry. The fringes were strongly dependent upon the angular setting, in that they were invisible at the rocking-curve maximum but increased in contrast and became more closely spaced away from the maximum. These experimental images were compared with the predictions of plane-wave dynamic theory, and a reasonably good correspondence was found when a finite beam divergence was taken into account. It was found that the theoretical fringe sequences depended upon the stacking fault and confirmed that the observed stacking faults were of intrinsic type.

W.Wierzchowski, M.Moore: Acta Crystallographica, 1995, A51[6], 831-40