Silver migration at the surface of ion-exchange waveguides: a plasmonic template

The formation and evolution of metallic-silver nanoparticles capped with silver oxide, in the surface of Ag-doped waveguides produced by ion-exchange, were characterized. The samples were exposed to air atmosphere for periods lasting until 35 days and their aging process was investigated by optical and Atomic Force Microscopy (AFM) measurements. The results evidence migration of the Ag super(+) cations from inside the glass to the surface at room temperature, followed by aggregation of the silver nanoparticles (NPs) and oxidation, creating a nanometric-thick layer over the waveguide surface. This layer was employed for surface-enhanced Raman scattering (SERS) signal and for the fabrication of holographic diffraction gratings (HDG), which are presented as application examples of this material as a new plasmonic template.