Nontrivial role of the resolution function in the formation of double-crystal X-ray rocking curves

作者：Chuev M A^*; Pashaev E M; Kvardakov V V; Subbotin I A

来源：Crystallography Reports, 2008, 53(5): 734-741.

DOI：10.1134/S1063774508050027

A theoretical analysis of the shape of the resolution function of an X-ray diffractometer in the double-crystal nondispersive scheme for measuring rocking curves has been performed. It is shown that this function, along with the strong narrow central line (corresponding to the characteristic line to which the collimator crystal and slits in the experimental scheme are tuned) always contains an additional weak satellite, corresponding to the neighboring characteristic line. This feature manifests itself in experimental curves as an additional pseudopeak, whose intensity is comparable with the corresponding diffraction scattering intensity from a sample in the fundamental characteristic line, and whose shape and exact position are set by the resolution function in a specific experimental scheme. It is shown that the exact allowance for the angular and spectral distribution of incident radiation in the double-crystal scheme makes it possible to precisely determine the parameters of the structures studied.

• 出版日期2008-9