Structure of Ag (110) and effect of surface roughness on LEED intensities

An analysis of low-energy electron diffraction (LEED) intensities from clean Ag (110) reveals that the truncated bulk crystal model with adjustment of the first interlayer spacing produces good to mediocre agreement with experiment for only about one half of 15 beams tested, and poor agreement for the remainder. Since no other reasonable model is found to do as well and, in addition, there is some experimental evidence for high step densities on the surface investigated, several attempts are made towards quantitative explanation of the discrepancies by means of the treatment of surface steps proposed earlier by Laramore, Houston and Park (J. Vac. Sci. Technol., vol.10, p.196 (1973)). Although these attempts are unsuccessful, the failure is ascribed to inadequacies of the treatment of the steps. The best model found for the atomic arrangement on the Ag (110) surface is a truncated bulk crystal with about 7% contraction of the first interlayer spacing along (110) as compared with the bulk.