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An accident that occurred at Bell Laboratories in 1925 started Clinton Davisson and Lester Germer on an historical series of experiments. While studying the backscattering of slow electrons from a polycrystallinenickel target, they observed that the angular distribution of the electrons changed completely when the surface was inadvertently oxidized at a high temperature. The consequent study of diffraction phenomena in electronsscattered from the (111) face of a nickel crystal confirmed the de Broglie hypothesis of the wave nature of electrons. But Davisson and Germer also predicted that this type of experiment would provide a valuable approach to the important problem of defining the precise position of atoms in the surfaces of crystalline solids. This suggestion has been pursued diligently by scientists both in the US and abroad. Now, fifty years after Davisson and Germer demonstrated the coherent scattering of electrons by a crystalline solid, the goal of studying surface structure with this technique is becoming a reality. In this article we will discuss some of the major advances of the past few years that are making this achievement possible.
Discrepancies that had cast doubt on the value of low‐energy electron diffraction as a tool for defining the positions of surface atoms have been resolved, and new techniques are enhancing its usefulness.