  The diffraction patterns of crystalline materials with local order contain
sharp Bragg reflections as well as highly structured diffuse scattering. The
instrumental requirements, experimental parameters and data processing
techniques for obtaining high-quality diffuse scattering data have previously
been determined for X-ray and neutron diffraction, but not yet for electron
diffraction. In this study, we show that the spatial resolution of the diffuse
scattering in three-dimensional electron diffraction (3D ED) data depends on
various effects, including the convergence of the electron beam, the point
spread function of the detector and the crystal mosaicity. In contrast to
single-crystal X-ray diffraction, the detector point spread function for 3D ED
is broader for a hybrid pixel detector than for a CCD. In our study, we also
compare the diffuse scattering in 3D ED data with the diffuse scattering in
single-crystal X-ray diffraction data and show that the diffuse scattering in
3D ED data can be obtained with a quality comparable to that from
single-crystal X-ray diffraction. As electron diffraction requires much smaller
crystal sizes than X-ray diffraction, this opens up the possibility to
investigate the local structure of many technologically relevant materials for
which no crystals large enough for single-crystal X-ray diffraction are
available.
