Interpretation of Electron Diffraction Patterns

TL;DR: In this paper, electron diffraction of small single crystals can be used for determination of the unit cell, enabling the X-ray lines to be indexed, and polycrystalline platy textures can sometimes be used, both to determine the unit cells and to provide indexed intensity data for use in structure analysis.

Abstract: Many minerals and synthetic inorganic phases of low symmetry occur only as fine powders or fibre aggregates. In such cases, determination of the unit cell from X-ray data alone can be difficult or impossible, because of failure to resolve multiple reflections or to detect weak ones on polycrystalline X-ray photographs, together with uncertainties about systematically absent reflections. However, electron diffraction of small single crystals can be used for determination of the unit cell, enabling the X-ray lines to be indexed. Alternatively, electron diffraction of polycrystalline platy textures can sometimes be used, both to determine the unit cell and to provide indexed intensity data for use in structure analysis. d-spacings and intensities measured on X-ray patterns are, however, generally more accurate and reliable than electron-diffraction data. Correlation of both sources of data can therefore yield information not available from either technique alone.