Publication Date:
1986-07-01
Description:
The basic Δω, Δ2θ technique for examining single-crystal Bragg reflections [Mathieson (1982). Acta Cryst. A38, 378-387] has recently been improved [Mathieson & Stevenson (1984). Aust. J. Phys. 37; 657-665], by using a simple experimental modification which reduces the source component to a minor (angular) role, thereby making the extraction (deconvolution) of the remaining components more accurate. The application of this new technique in the determination of reflectivity (rocking) curves for imperfect crystals has been demonstrated [Mathieson & Stevenson (1985). Acta Cryst. A41, 290-296]. In the present case, the examination of individual reflections from a small single crystal of CuInSe2 reveals that the improved technique is capable (i) of identifying, by its locus extension in Δω, Δ2θ space, diffraction from one side of the specimen crystal to the other (in the diffraction plane), even for a crystal of average dimension ~0.06 mm, and (ii) of estimating the reflectivity curve for different parts of the crystal. A series of model eases is discussed, to clarify the interpretation of observed two-dimensional intensity distributions. While considered here in relation to a small crystal, this technique is applicable to extended-plate crystals (in transmission mode) by a selected-area procedure.
Print ISSN:
0108-7673
Electronic ISSN:
2053-2733
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
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