Structure and diffracted intensity in a model for irreversible island‐forming chemisorption with domain boundaries

Abstract

<p>Despite the awareness that island‐forming chemisorption is often kinetically limited and intrinsically nonequilibrium, there is little sophisticated analysis of the corresponding island structure or diffracted intensity. Here we analyze a model where species irreversibly and immobilely chemisorb (commensurately) from a precursor source, with distinct rates for island nucleation (chemisorptionin an empty region) and growth (chemisorption at island perimeters), the latter rates being larger. Specifically, we consider the formation of one‐dimensional double‐spaced islands, and two‐dimensional checkerboard C(2×2) islands on a square lattice. In both cases (permanent) domain boundaries form between out‐of‐phase islands. We analyze scaling of the saturation coverage, a characteristiclinear island dimension, spatial correlations, etc., with the ratio of growth to nucleation rates. The structure of individual islands, and of the saturation domain boundary ‘‘network’’ are elucidated. The corresponding diffracted intensity exhibits significant interference at superlattice beams, and diminution at integral order beams as saturation is approached.</p>