The aim of the procedure was to determine the displacement vector, R, at the fault plane without access to prior knowledge concerning it. The technique was suitable for both diffraction contrast imaging and for de-focus convergent-beam electron diffraction studies. The extinctive reflection which corresponded to a phase shift of multiples of 2 in a systematic row (g, 2g, 3g, ...) was used to determine the fractional part of the dot product, g•R. The displacement vector was determined uniquely from the fractional parts of gi•R for 3 reflections (i = 1, 2, 3), which just formed a primitive cell of the reciprocal lattice. The intrinsic/extrinsic nature of a stacking fault in a face-centered cubic crystal was obtained directly from the relationship between R and the foil normal. In addition, all of the stacking faults and antiphase boundaries in a thin foil could be revealed by diffraction contrast experiments for only 3 reflections which formed a primitive cell of the reciprocal lattice. The present method for determining the intrinsic/extrinsic nature of a stacking fault directly from R did not rely upon the symmetry properties of dark-field images of the fault and involved no prior conclusion to be drawn concerning the thin foil/fault geometry. In principle, the procedure was applicable to various stacking faults and antiphase boundaries, and was expected be useful for the analysis of other planar defects in crystals.

J.Feng, R.Wang, H.Zou: Philosophical Magazine A, 1995, 72[4], 1121-30