Auger electron spectroscopic evidence for laser damage on silver electrodes exhibiting surface-enhanced Raman scattering

Abstract

Silver electrode surfaces which exhibited the surface-enhanced Raman scattering (SERS) effect were examined for evidence of laser damage by scanning electron and scanning Auger microscopy (SEM/SAM). The laser illuminated area of the silver electrodes which are the origin of the pyridine SERS effect are localized zones (ca. 0.03 mm diameter) of pure or nearly pure carbon. The carbon is thought to originate primarily in the laser-assisted carbonization of pyridine (free or coordinated to anodically generated silver(I)). The SERS electrode from the Ag/KCN, Na2SO4(H2O) system exhibits more extensive laser damage than the pyridine system. In the cyanide system, the composition of the laser damage zone is complex, being richer in K, O, and S but depleted in Ag and C relative to the nonilluminated surface. Cathodically cleaned surfaces exhibited no evidence for laser damage. Show more