A method was described for showing how electron channelling could be successfully applied to the determination of the substitutional and interstitial lattice sites of atoms in crystals. The experiments were carried out in a conventional transmission electron microscope which was equipped with an X-ray detector. The method involved the detailed measurement of channelling profiles, as well as the calculation of such profiles. A fitting procedure permitted the determination of the location of specific atoms within the elementary cell. It was found that a good fit was obtained only when the interference of Bloch waves, X-ray production by inelastically scattered electrons, delocalization of the inner-shell ionization event, and the crystal thickness and shape were taken into account in the calculations. The applicability of the method was demonstrated by applying it to the known crystal structures of Mo and GaAs.

W.Nüchter, W.Sigle: Philosophical Magazine A, 1995, 71[1], 165-86