ANALYSIS OF SINGLE CRYSTAL DIFFRACTION PROFILES, THEORY AND EXPERIMENTS. Joachim Lange, Institut für Angewandte Physik, Lehrstuhl für Kristallographie, Universität Erlangen-Nürnberg, Bismarckstraße 10, 91054 Erlangen, Germany

Diffraction profiles contain information on real crystal properties such as the angular and the radial mosaic spread. Furthermore, the knowledge of theoretically calculated profiles permits a better handling of measured weak reflections and the correction of systematic errors within collected data sets.

The calculation of reflection profiles from single crystals is successful only at knowledge of several experimental components. The most important components, which influence the line profile shape, are the spectral and intensity distribution of the virtual focus from the incident radiation [1], the shape and absorption of the crystal polyhedron [2], the mosaic block distribution and TDS [3].

Experimental procedures and the theoretical background for the determination of these quantities are presented and discussed. Furthermore a model for the mosaic block distributions from single crystals and the theoretical calculations are presented, which agree very good with experimentally determined data.

[1]Lange, J.: Analysis of reflection profiles. ECM-16 Abstracts (1995), 160.

[2]Zimmermann, S., Lange, J., Burzlaff, H.: Zur Vermessung von Einkristallpolyedern mit Hilfe einer CCD-Kamera, Z. Krist., Suppl. No. 9 (1995), p. 388.

[3]Rouse, K. D., Cooper, M. J.: The Correction of Measured Integrated Bragg Intensities for Anisotropic Thermal Diffuse Scattering, Acta Cryst. A25 (1969) 615-621.