MINIMUM ENERGY CONFIGURATIONS OF ATOMS ADSORBED ON A LATTICE

The minimum energy arrangements of atoms adsorbed on a crystalline surface display a very rich set of geometries originated from the competition between the adsorbate-adsorbate interaction, and the tendency to occupy the most favorable adsorption sites over the substrate. We develop a method to obta...

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Bibliographic Details
Authors: Arce, H, MOCHAN, WL, COCHO, G
Format: article
Status:Published version
Publication Date:1993
Country:México
Institution:Universidad Nacional Autónoma de México
Repository:Sistema de Información de la Facultad de Ciencias, UNAM
OAI Identifier:oai:repositorio.fciencias.unam.mx:11154/3465
Online Access:http://hdl.handle.net/11154/3465
Access Level:Open access
Keyword:Chemistry, Physical
Physics, Condensed Matter
Description
Summary:The minimum energy arrangements of atoms adsorbed on a crystalline surface display a very rich set of geometries originated from the competition between the adsorbate-adsorbate interaction, and the tendency to occupy the most favorable adsorption sites over the substrate. We develop a method to obtain these geometries for rational coverages assuming the adsorbates occupy symmetric sites and that they form a lattice commensurate with the substrate, allowing for multi-atomic primitive cells. We obtain results for adsorption on a square lattice with truncated-dipolar interactions. We propose a new truncation scheme which we compare with previous ones, and we explore the effects of changing the range of the potential. The ordered phases we obtain agree with experiments performed for K over Ir(001) and Cs over Rh(001). Furthermore, our results supply some insight on the absence of observed ordered phases for some rational coverages.