Full structural determination of the GaAs(110)-p(1x1)-Sb (1 ML) surface using chemical-shift photoelectron diffraction

A detailed quantitative structure determination of the GaAs(110)-p(1x1)-Sb interface has been undertaken using scanned-energy-mode photoelectron diffraction from the two chemically shifted components of the Sb-4d core level, over a wide range of emission angles. Analysis of the data set by approximate direct methods, and by a multiple scattering trial-and-error fitting optimization lead to a consistent structure in which the two-inequivalent Sb adatoms can be identified following an epitaxial continued layer structure. The structural parameters were refined by a search in multiparameter space combining systematic calculations of grids and the use of an automated algorithm based on the Gauss-Newton procedure. Several improvements to the chemical-shift photoelectron diffraction analysis methodology, including simultaneous multidimensional optimization, and the influence of the Cooper minimum in the diffraction effects have been described. [S0163-1829(98)05843-3].