INVESTIGADORES
RAMIREZ PASTOR Antonio Jose
artículos
Título:
Adsorption of a Lennard- Jones gas on random bivariate surfaces.
Autor/es:
A. J. RAMIREZ-PASTOR; D. STACCHIOLA; M. NAZZARRO; J. L. RICCARDO; G. ZGRABLICH
Revista:
SURFACE SCIENCE
Editorial:
Elsevier
Referencias:
Año: 2000 vol. 449 p. 43 - 49
ISSN:
0039-6028
Resumen:
Adsorption of a monatomic gas with LennardJones lateral interactions is studied on a heterogeneous surface
represented by a square lattice of sites. Adsorption sites can be of two kinds, strong and weak sites, in equal
concentration and distributed at random. The lattice parameter (distance between nearest-neighbor sites) is also varied
to obtain different situations for the lateral interaction among first, second, etc. order neighbors.
The temperature is fixed in such a way that ordered adsorbate phases can be formed and the adsorption isotherm
and isosteric heat of adsorption are studied through Monte Carlo simulation, changing the different parameters of
the model. A rich variety of different behaviors is found and analyzed in the context of the lattice-gas model. Further
comparison is carried out between the simulation and the effective substates approximation (ESA) introduced recently
[Riccardo et al., J. Chem. Phys. (1999) in press]. It is found that ESA reproduces very well the coverage dependence
of the chemical potential for lattices where only attractive interactions are present. In the case of lattices where order
disorder phase transitions take place due to repulsive interactions, ESA predictions are fairly good only when the
heterogeneity is large compared with lateral interactions.fferent situations for the lateral interaction among first, second, etc. order neighbors.
The temperature is fixed in such a way that ordered adsorbate phases can be formed and the adsorption isotherm
and isosteric heat of adsorption are studied through Monte Carlo simulation, changing the different parameters of
the model. A rich variety of different behaviors is found and analyzed in the context of the lattice-gas model. Further
comparison is carried out between the simulation and the effective substates approximation (ESA) introduced recently
[Riccardo et al., J. Chem. Phys. (1999) in press]. It is found that ESA reproduces very well the coverage dependence
of the chemical potential for lattices where only attractive interactions are present. In the case of lattices where order
disorder phase transitions take place due to repulsive interactions, ESA predictions are fairly good only when the
heterogeneity is large compared with lateral interactions.fferent parameters of
the model. A rich variety of different behaviors is found and analyzed in the context of the lattice-gas model. Further
comparison is carried out between the simulation and the effective substates approximation (ESA) introduced recently
[Riccardo et al., J. Chem. Phys. (1999) in press]. It is found that ESA reproduces very well the coverage dependence
of the chemical potential for lattices where only attractive interactions are present. In the case of lattices where order
disorder phase transitions take place due to repulsive interactions, ESA predictions are fairly good only when the
heterogeneity is large compared with lateral interactions.fferent behaviors is found and analyzed in the context of the lattice-gas model. Further
comparison is carried out between the simulation and the effective substates approximation (ESA) introduced recently
[Riccardo et al., J. Chem. Phys. (1999) in press]. It is found that ESA reproduces very well the coverage dependence
of the chemical potential for lattices where only attractive interactions are present. In the case of lattices where order
disorder phase transitions take place due to repulsive interactions, ESA predictions are fairly good only when the
heterogeneity is large compared with lateral interactions.ffective substates approximation (ESA) introduced recently
[Riccardo et al., J. Chem. Phys. (1999) in press]. It is found that ESA reproduces very well the coverage dependence
of the chemical potential for lattices where only attractive interactions are present. In the case of lattices where order
disorder phase transitions take place due to repulsive interactions, ESA predictions are fairly good only when the
heterogeneity is large compared with lateral interactions.