Campus Units
Physics and Astronomy, Mathematics, Ames Laboratory
Document Type
Article
Publication Version
Published Version
Publication Date
1994
Journal or Book Title
Physical Review E
Volume
50
Issue
6
First Page
4302
Last Page
4316
DOI
10.1103/PhysRevE.50.4302
Abstract
Here, we consider discontinuous nonequilibrium phase transitions to poisoned or ‘‘adsorbing’’ states in lattice-gas models of surface reactions. Specifically, we examine the monomer or CO-poisoning transition in the Ziff-Gulari-Barshad monomer-dimer reaction model for CO oxidation, modified to include adspecies diffusion. For CO pressures below the poisoning transition, we first characterize the propagation of and fluctuations at an interface between reactive and CO-poisoned states. Here, we utilize ideas from spatial contact models, reaction-diffusion theory, and kinetic roughening theory. Evolution is described by the Kardar-Parisi-Zhang equation, but with the nonlinearity and kinetic surface tension vanishing on approaching the transition. Next, again for CO pressures below the transition, we consider the evolution of a ‘‘nucleus’’ of the reactive state embedded in the CO-poisoned state, now exploiting concepts from epidemic theory. We elucidate the divergence and ‘‘sharpening’’ of the critical size of this nucleus, both approaching the transition and with increasing adspecies diffusion rates. The deviation from mean-field divergence approaching the transition is related to the vanishing of the kinetic surface tension. The sharpening is related to the reduced influence of fluctuations. Throughout this contribution, we focus on providing a unifying framework that can describe both the fluctuation-dominated behavior of the lattice-gas model for low adspecies diffusion rates, and the crossover to the deterministic mean-field behavior for high diffusion rates where the adlayer is well mixed or randomized.
Copyright Owner
American Physical Society
Copyright Date
1994
Language
en
File Format
application/pdf
Recommended Citation
Evans, James W. and Ray, T. R., "Interface propagation and nucleation phenomena for discontinuous poisoning transitions in surface-reaction models" (1994). Physics and Astronomy Publications. 398.
https://lib.dr.iastate.edu/physastro_pubs/398
Included in
Biological and Chemical Physics Commons, Statistical, Nonlinear, and Soft Matter Physics Commons
Comments
This article is published as Evans, J. W., and T. R. Ray. "Interface propagation and nucleation phenomena for discontinuous poisoning transitions in surface-reaction models." Physical Review E 50, no. 6 (1994): 4302, doi:10.1103/PhysRevE.50.4302. Posted with permission.