IRRADIATION-INDUCED AG-COLLOID FORMATION IN ION-EXCHANGED SODA-LIME GLASS

Ion-exchanged glass samples were obtained by immersing soda-lime slide s in molten salt baths of molar concentration in the range 1-20% AgNO3 in NaNO3, at temperatures varying from 320 to 350 degrees C, and proc essing times of the order of a few minutes. Irradiations of exchanged samples were subsequently performed by using H+, He+, N+ ions at diffe rent energies in order to obtain comparable projected ranges. The flue nce was varied between 5 x 10(15) and 2 X 10(17) ions/cm(2). Most of t he samples were treated at current densities lower than 2 mu A/cm(2), in order to avoid heating effects. Some samples were irradiated with 4 keV electrons, corresponding to a range of 250 nm. The formation of n anoclusters of radii in the range 1-10 nm has been observed after irra diation, depending on the treatment conditions. The precipitation proc ess is governed by the electronic energy deposition of incident partic les. The most desirable results are obtained for helium implants. The process was characterized by the use of Secondary Ion Mass Spectrometr y (SIMS) and nuclear techniques (Rutherford Backscattering (RES), Nucl ear Reactions (NRA)), in order to determine concentration-depth profil es and by optical absorption and Transmission Electron Microscopy (TEM ) measurements for the silver nanoclusters detection and size evaluati on.