Formation of silver halide monolayer on Au-covered Ag(111) in alkali halide solution

When Ag(111) films covered with a few nanometer thick Au film are placed in a dilute alkali bromide or chloride solution, the corresponding silver halide monolayer forms on top of the Au surface. This unique solid/liquid interfacial phenomenon likely involves a solid-phase material transfer of silver from the underlying Ag(111) substrate across the thin Au overlayer. The AgX monolayer formed in this way is unusually stable in the atmosphere, and seems to have an atomic arrangement close to that in the real AgX(111) structure.