Surface enhanced Raman spectra of oxygen adsorbed on silver

Abstract Silver films deposited in ultra high vacuum at 120 K and exposed to relatively low doses (up to 1000 L) of molecular oxygen display Raman vibrational bands at 697 and 1053 cm−1, assigned to nominally peroxidic and superoxidic dioxygen. Oxygen exposure during operation of the ion getter pump leads to further Raman bands which might indicate further adsorption states of oxygen at rough silver surfaces.