A report on speckle and coherent diffraction phenomena in selected-area transmission electron diffraction patterns

Abstract

This paper presents a report on coherent interference effects in selected-area transmission electron diffraction patterns. In particular, it is shown that the coherent small-angle scatter seen around the centrally transmitted beam from nanocrystalline materials is similar to the speckle patterns that occur when a laser diffracts from a disordered sample. Laser speckle patterns are used routinely to study dynamic parameters of colloidal solutions and it is suggested that similar experiments could be performed with electrons. The significance of this lies in the relative wavelengths of the two radiations and, thus, instead of colloidal particles, atomic-scale dynamics could be studied. © 1994.