Device for visualizing the atomic structure of surface layers based on an electron focusing effect

A description is given of a simple device for visualizing the atomic struct ure of surface layers by recording the focusing maxima in the spatial distr ibution of 1-3 keV electrons reflected from a sample with energy losses up to approximate to 300 eV. This is based on a wide-angle retarding-field ene rgy analyzer with a microchannel electron flux analyzer and video system fo r data acquisition and processing, which can obtain data at a rate of up to 50 distributions per second, allowing the dynamics of structural rearrange ments to be studied in a surface region approximately 15 Angstrom thick. Th e low primary electron beam current (0.1 mu A) minimizes the electron-stimu lated effects on the object being studied. (C) 1998 American Institute of P hysics. [S1063-7842(98)01512-8].