COMMENSURATE AND INCOMMENSURATE INDIUM PHASES ON A (111)A INAS SURFACE

Adsorption phases of indium on a (111)A InAs surface are investigated. Three phases are detected: (2x2)(a), (1x1), and the (0.77x0.77) incom mensurate phase. The (0.77x0.77) incommensurate phase is modeled as a densely packed (111) layer of In (fcc) crystal situated in epitaxial r elation to the InAs substrate: [110](In)parallel to[110](InAs). Reason s for the realization of the fee crystal structure are analyzed. It is shown that the incommensurate phase is spatially modulated by the per iodic potential of the substrate. A comparison of our data on indium a dsorption onto (111) InAs with the data in the literature on indium ad sorption onto (111) Si, Ge reveals the importance of relaxation of the elastic strains in the formation of two-dimension adsorption-induced superstructures. (C) 1998 American Institute of Physics.