Small-angle X-ray scattering from growing ice crystals revealed sharp diffraction peaks at various reflection angles. The peaks had low intensities, and rose and fell with a relaxation time of 100 to 1000s. The small widths indicated the existence of superstructures with well-defined dimensions. A quantitative analysis showed that these dimensions conformed to the distances, in coincident site lattices, that were generated by 2 hexagonal ice lattices that were slightly rotated with respect to each other. It was concluded that the sharp small-angle X-ray scattering reflections were caused by arrays of edge dislocations in low-angle grain boundaries that developed during the growth of ice crystals. They disappeared during recrystallization.

J.Van der Elsken, W.Bras, J.Dings, J.C.F.Michielsen: Physical Review B, 1996, 54[5], 3110-4