Effects of adsorption site and surface stress on ordered structures of oxygen adsorbed on W(110)

Abstract

Ordered phases of O on W(110) entail compressive surface stress, the manifestations of which are directly observed for different coverages using scanning tunneling microscopy. Low coverage adsorption results in a gas phase with disordered persistent structures. At higher coverage, ordered phases condense with disordered domains. O adsorption in the two distinct triply coordinated sites of the W(110) unit cell leads to separate domains with the adsorption site exchanged. Annealing relieves compression within high coverage phases by the formation of site-exchange domain superstructures. © 1993 The American Physical Society.