Stereographic X-ray reflection topography of dislocations in zinc

X-ray reflection topographs were taken of a zinc surface oriented about 1° from a basal plane. Basal dislocations are revealed in the topographs, and their apparent depth was determined using stereo pairs of topographs. The apparent depths observed in a complimentary pair of topographs using 103 and 013 reflections were significantly greater than those observed in an asymmetric pair of topographs in which the same 103 reflection was used. This difference is attributed to shifts of the image with respect to the dislocation position. Quantitative estimates of the image shifts and the actual depths of the observed dislocations are obtained from the measurement of apparent depths. Dislocations are visible over the range of depths from 1.7 to 4.5 μm.