ISSN:
1572-9613
Keywords:
Surface diffusions
;
random walks
;
lattices
;
periodic traps
;
dissociation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Nitrogen adsorption on stepped W(110) surfaces is examined to illustrate a theory of surface kinetics. Experimental findings by Besockeet al. have shown that nitrogen chemisorbs dissociatively only at the step corner sites of a W(110) surface. Thus the rate of dissociation reveals the mobility of nitrogen and its interaction with the surface. Using continuous-time-random-walk theory, we obtain the probability that molecules reach the step corner sites as a function of time. A kinetic model of nitrogen dissociation is proposed to calculate a coverage function that is in good agreement with experiment. The surface diffusion constant of nitrogen molecules is obtained and is in accordance with previous observations that nitrogen molecules are first weakly physisorbed on the W(110) terrace. Finally, the coverage functions for different step densities are predicted.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01012327
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