Stability of underpotentially deposited Ag layers on a Au(111) surface studied by surface X-ray scattering

摘要

Stability of underpotentially deposited (upd)Ag layers on Au(1 11) surface was investigated by surface X-ray scattering (SXS). While the complete pseudomorphic Ag bilayer on Au(1 11) surface obtained by upd at 10 mV (vs. Ag/Ag~+) was maintained its structure even after the circuit was disconnected and the surface was exposed to ambient atmosphere, the pseudomorphic Ag monolayer obtained by upd at 50 my was converted to a partial bilayer with the coverage of 0.66 and 0.46 ML for the 1st and 2nd layer, respectively. These results show that Ag bilayer is structurally more stable than Ag monolayer on Au(1 11) and Ag atoms of the upd monolayer move around on the Au(1 11) surface without potential control.