Diffusion and aggregation of implanted Ag and Au in a lithia--alumina--silica glass

Optical extinction and Rutherford backscattering (RBS) techniques were employed to obtain information on the size and spatial distribution of Au- and Ag-colloids in implanted (Au+, Ag+) lithia-alumina-silica glass. The formation of metallic aggregates (colloids), necessary for preparation of a glass-ceramic surface layer, proceeds readily with annealing temperature for Au-implanted samples but not for Ag-implanted material. The optical and RBS spectra show that the particle size and spatial distribution in as-implanted samples are sensitive to sample temperature and ion-beam heating effects, while these parameters for Au-implanted samples are relatively insensitive to temperature and beam current. It is suggested that this behavior is related to differences in the dissolution energies of Ag and Au aggregates. A two-peaked spatial distribution for Ag implanted at room temperature at a dose rate of approximately 1 μA/cm2 is observed which may result from the trapping of Ag in the compacted damage region of the glass during implantation. (auth)