Analysis and Modeling of Spatial Distributions of Adatoms on Metal Surfaces: The Role of Anisotropic Exclusion Zone

Several parameters could affect the spatial distribution of particles in an anisotropic environment. To disentangle these effects, a thorough comparison between experimental and simulated data is necessary. Fluorine atoms adsorbed on the Ag(110) surface are used as a case study. First neighbor distance and Voronoi tessellation analysis reveal deviations from a purely random distribution, indicating the presence of spatial correlation. Further insights are provided by the pair correlation function, which reveals a rectangular exclusion zone aligned with the crystallographic axes of the Ag(110) substrate. Monte Carlo simulations have been performed, incorporating key factors such as the anisotropic surface geometry, the anisotropic exclusion zone, and the different adsorption probabilities of the adatoms. These results suggest that within this set of parameters the anisotropic exclusion zone plays the main role in shaping the spatial distribution of adatoms, shedding light on the interplay between substrate structure and adsorption processes.