X-ray scattering by crystals with local lattice rotation fields

X-ray (or neutron) scattering by crystals with local rotation fields arisin g from dislocations is treated on the basis of the formalism of the kinemat ical diffraction theory. Such fields mostly change the intensity distributi on of reflections in the azimuthal plane. Scattering intensity in the azimu thal plane for crystals with one or two sets of different-type dislocation walls, causing local rotations in the lattice, is analysed. In this case th e intensity distribution is close to Lorentzian in the radial direction and to Gaussian in the azimuthal direction. The expressions for the scattering intensity are valid when averaging over a large statistical ensemble of de fects. If this condition is ndt fulfilled, the intensity distribution in th e azimuthal plane will split into several spikes. The mean distance between these spikes in the reciprocal-lattice space is connected with the disorie ntation between the walls. The conditions necessary far such splitting of t he reflection into spikes are considered. The values of the limiting disori entation angle for some common scattering volumes and distances between dis location walls are evaluated.