Phases Transitions and Adsorption Isotherm in Multilayer Adsorbates with Lateral Interactions

S. CASAL; S. H. WIO; S. E. MANGIONI

PHYSICA A - STATISTICAL AND THEORETICAL PHYSICS

Elsevier North Holland

Año: 2002 vol. 311 p. 443 - 457

0378-4371

We analyze here a model for an adsorbate system composed of many layers by extending a theoretical approach used to describe pattern formation on a monolayer of adsorbates with lateral interactions. The approach shows, in addition to a 1rst-order phase transition in the 1rst layer, a transition in the second layer together with evidence of a "cascade" of transitions if more layers are included. The transition pro1les, showing a staircase structure, corroborate this picture. The adsorption isotherm that came out of this approach is in qualitative agreement with numerical and experimental results. We analyze here a model for an adsorbate system composed of many layers by extending a theoretical approach used to describe pattern formation on a monolayer of adsorbates with lateral interactions. The approach shows, in addition to a 1rst-order phase transition in the 1rst layer, a transition in the second layer together with evidence of a "cascade" of transitions if more layers are included. The transition pro1les, showing a staircase structure, corroborate this picture. The adsorption isotherm that came out of this approach is in qualitative agreement with numerical and experimental results.