OXYGEN DISSOCIATION ON AG(110) - A RUIN GAME

The previously reported dependence of the dissociative sticking probab ility of oxygen on the Ag(110) surface has been modeled as a random wa lk between selective adsorption and desorption sites on the surface. C hemisorbed oxygen molecules are allowed to move on an anisotropic surf ace between boundaries representing the Ag-O added rows and surface st eps. Molecules that encounter the added rows are forced to desorb from the surface, while molecules reaching a step react, forming Ag-O unit s, and become permanently bound. Although simple, the model describes the form and magnitude of the sticking probability as a function of th e surface atomic oxygen coverage with only limited and physically reas onable fitting parameters. (C) 1997 Elsevier Science B.V.