Electron enhanced sorption of fluorine by silver surfaces

Abstract

Quartz crystal microbalance measurements indicate a multilayer adsorption of fluorine occurs at a relatively high rate during exposure of a silver surface to F 2 or XeF 2. As more fluorine is adsorbed our results indicate that it reacts chemically with the silver forming AgF. The rate of fluorine adsorption from XeF 2 increases whereas the rate of adsorption of F 2 remains constant, when this occurs. When a flux of electrons is simultaneously incident on a silver surface along with a flux of F 2 or XeF 2 the fluorine adsorption rates increase greatly. 1000 Å thin films of ThF 4, MgF 2, SiO 2 and Al 2 O 3 present relatively minimal barriers to fluorine uptake. The fluorine uptake actually occurs faster if a fluoride film is deposited on silver as opposed to an oxide film or no film at all. Gold films were not found to exhibit this behavior.