Surface phase transitions in one-dimensional channels arranged in a triangular cross-sectional structure: Theory and Monte Carlo simulations
Monte Carlo simulations and finite-size scaling analysis have been carried out to study the critical behavior in a submonolayer lattice-gas of interacting monomers adsorbed on one-dimensional channels arranged in a triangular cross-sectional structure. Two kinds of lateral interaction energies have...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2006 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/170754 |
| Acceso en línea: | http://hdl.handle.net/11336/170754 |
| Access Level: | acceso abierto |
| Palabra clave: | LATTICE GAS MODELS PHASE TRANSITIONS MONTE CARLO SIMULATIONS https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
| Sumario: | Monte Carlo simulations and finite-size scaling analysis have been carried out to study the critical behavior in a submonolayer lattice-gas of interacting monomers adsorbed on one-dimensional channels arranged in a triangular cross-sectional structure. Two kinds of lateral interaction energies have been considered: (1) wL, interaction energy between nearest-neighbor particles adsorbed along a single channel and (2) wT, interaction energy between particles adsorbed across nearest-neighbor channels. We focus on the case of repulsive transverse interactions (wT >0), where a rich variety of structural orderings are observed in the adlayer, depending on the value of the parameters kB T wT (being kB the Boltzmann constant) and wL wT. For wL wT =0, successive planes are uncorrelated, the system is equivalent to the triangular lattice, and the well-known (3×3) [(3×3)*] ordered phase is found at low temperatures and a coverage, θ, of 13 [23]. In the more general case (wL wT 0), a competition between interactions along a single channel and a transverse coupling between sites in neighboring channels leads to a three-dimensional adsorbed layer. Consequently, the (3×3) and (3×3)* structures "propagate" along the channels and new ordered phases appear in the adlayer. Each ordered phase is separated from the disordered state by a continuous order-disorder phase transition occurring at a critical temperature, Tc, which presents an interesting dependence with wL wT. The Monte Carlo technique was combined with the recently reported free energy minimization criterion approach (FEMCA) [F. Romá, Phys. Rev. B 68, 205407 (2003)] to predict the critical temperatures of the order-disorder transformation. The excellent qualitative agreement between simulated data and FEMCA results allows us to interpret the physical meaning of the mechanisms underlying the observed transitions. |
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