Physics and Astronomy, Mathematics, Ames Laboratory
Journal or Book Title
Physical Review B
During chemisorption, islands often form in which adspecies have superlattice spacing. Upon meeting, these coalesce if in phase, and form a domain boundary otherwise. Manifestly nonequi- librium island distributions can develop as a result of kinetic limitations, and a metastable saturation state of domain boundaries may, in turn, result. We analyze irreversible cooperative filling models for the formation of c(2×2) islands, where island structure is kinetically determined, and extensive coalescence near saturation produces a ‘‘percolative’’ domain structure. We show that the associated dramatic increase in domain size, and fractal domain structure, are not reflected in the spatial pair-correlation or diffracted-intensity behavior. Consequently, we identify quasi-one-dimensional measures of domain size which better reflect correlation-length behavior. These are then used to develop scaling relations for pair correlations and diffracted intensities. A special case of our model describes metastable c(2×2)O/Fe(001) formed after exposure of Fe(001) to H2O.
American Physical Society
Evans, James W. and Nord, R. S., "Nonequilibrium c(2×2) island formation during chemisorption: Scaling of spatial correlations and diffracted intensity" (1988). Physics and Astronomy Publications. 413.