The driving force for (px√3)⇆(1x1) phase transition of Au(111) in the presence of organic adsorption:: a combined chronocoulometric and surface X-ray scattering study

In situ X-ray scattering and chronocoulometric experiments were performed to assess the influence of adsorption of pyridine, 2,2'-bipyridine and uracil on the driving force for the (p x root 3)-->(1 x 1) transition of the Au(111) surface. We have shown that the overall driving force is a combination of the driving force due to charge and the driving force due to the adsorbate. We have estimated the magnitude of the two driving forces and have given the upper and lower limits to this estimate. Our results show that the two driving forces are of comparable magnitude and that the interpretation of the surface reconstruction phenomena given in terms of either purely charge or a purely adsorbate effect is an oversimplification. (C) 1998 Elsevier Science S.A. All rights reserved.