On the description of argon adsorption on graphite for temperatures below the 2D-critical temperature

摘要: Abstract Computer simulations have been carried out in order to study the adsorption of argon on planar graphite substrates shed light evolution physical structure adsorbate as a function pressure. Planar are generally modelled having an infinite extent using periodic boundary conditions (PBCs) directions parallel surface, take advantage simple expression for adsorbate-adsorbent interaction energy. This model has proved be successful description experimental isotherms at temperatures above 2D-critical temperature first layer, T2D,c. However, it fails below T2D,c because application PBCs results number unphysical sub-steps isotherm course formation layer. It is shown here that these anomalous steps arise from interactions molecules main box with image boxes, creating artefact domains and gaps adsorbate. To overcome this we propose 2D-model substrate finite dimensions thereby removing artificial boxes. Applied find 2D describes better than model, especially temperature. These suggest free plays important role 2D-condensation.