ISSN:
1432-0630
Keywords:
82.65J
;
82.20
;
68.35R
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract The model recently proposed by Ziff et al. [1] for reactions of the type A+(1/2)B 2 → AB is extended in order to study the effect of A-desorption on irreversible (kinetic) phase transitions (IPT). The IPT from a stationary state with AB-production to a B-poisoned state is not influenced by A-desorption. On the other hand, desorption of A-species prevents the existence of a truly A-poinsoned state. Therefore the IPT from the stationary regime to an A-poisoned state does not occur but an apparent phase transition is observed for small values of the desorption probability (P D). The rate of AB-production (R AB ) crosses over from a regime where it becomes dominated by the rate of A-adsorption, when the coverage with A-species is negligible to another regime where R AB is dominated by the rate of B 2-adsorption, when the coverage with B-species is negligible. Within the former regime, R AB decays exponentially with the mole fraction of A-molecules in the gas phase and exhibits a power law dependence with P D (exponent γ=2).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00334228
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