title: Detailed characterization of (3 x 3) iodine adlayer on Pt(111) by unequal-sphere packing model.
abstract: A simple unequal-sphere packing model is applied to study the iodine (3x3) adlayer on the Pt(111) surface. By using a newly introduced parameter, defined as the average adsorbate height, three characteristic adlattices, (3x3)-sym, (3x3)-asym, and (3x3)-lin, have been selected and characterized in great detail, including the exact adatom registry. The (3x3)-sym iodine adlattice, observed in many experimental studies, appears to be, on average, the closest one to the substrate surface. A special contour plot of average adsorbate height vs X and Y positions of the (3x3) iodine unit cell indicates the existence of two local minima, which are related to preferential formation of (3x3)-sym and (3x3)-asym iodine adlattices. Our model gives good agreement with experimental findings, and explains the mechanism of preferential appearance of (3x3)-sym and (3x3)-asym structures.
authors.affiliation: Laboratorio de Nanotecnologia e Ingenieria Molecular, Area de Electroquimica, Departamento de Quimica, Avenida San Rafael Atlixco No. 186, Col. Vicentina, Del. Iztapalapa, Caixa Postal 09340 Mexico, Distrito Federal Mexico.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Tkatchenko
authors.forename: Nikola
authors.initials: N
authors.lastname: Batina