Ewald construction for surfaces. (a) Ewald construction for a standard 4 grid LEED optics. (b) Modified Ewald construction for spot profile analyzing LEED (SPA-LEED). The curvature of the SPA-LEED scan is reduced by a factor of .
Alignment algorithm for reciprocal space maps. At low electron energy offset voltages are applied, at higher electron energy the position of the sample is optimized. If both steps are iterated, the position of the LEED pattern will eventually remain constant.
Screenshots from the SPA-LEED software, Version 4.1d. (a) The initial energy of the reciprocal space map is selected in packet0. (b) The first field in packet1 records a linescan with the given parameters. (c) Energy values of cause the software to change the electron energy to .
Reciprocal space maps of the Au induced faceting of vicinal Si(001). The (110)-(001) section of the reciprocal space is shown. (a) Before adsorption of Au at . The lattice rods of the double step train are inclined by 4° with respect to the (001) orientation. (b) After adsorption of Au. The surface decayed into (001) terraces and (119) facets, which are both larger than the transfer width of the SPA-LEED.
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