EXAFS STUDY ON AG-DOPED SILICATE-GLASSES IRRADIATED WITH LOW-MASS IONS

We present an EXAFS study on Ag-doped soda-lime glass waveguides obtai ned by ion-exchange and treated by low-mass ion-irradiation to promote the formation of metallic clusters. For differently prepared samples we have determined the Ag local order before and after the treatment. In the as-exchanged glasses Ag is coordinated with O at a distance sig nificantly shorter than the Na-O bond length in the unexchanged glass. In irradiated samples we found the formation of metal aggregates. Str uctural parameters of clusters in high-temperature irradiated sample a re compatible with a compressed fee structure while in room-temperatur e irradiated specimen a more complicated structure comes out.