Enhanced fluorescence from Eu3+ owing to surface plasma oscillation of silver particles in glass

We describe the increase of europium ion (Eu3+) fluorescence owing to resonant plasma oscillation of silver (Ag) particles in silica (SiO2) glass, which were precipitated by annealing in a reducing atmosphere sol-gel derived SiO2 glass containing Ag+ and Eu3+ ions. Nanometer size effects of Ag particles on the increase were also invest as a function of the reduction time. The mean particle size and the volume fraction of silver particles in glass were estimated from absorption spectra using the Mie-Drude theory modified by the electron mean free path model. The fluorescence from Eu3+ ions when the excitation was a N-2 laser increased in the presence of silver particles of similar to 4.3 nm size. From comparison of the radiative damping time of the plasma oscillation with the lifetime of Eu3+ fluorescence we, tentatively, concluded that the induced surface plasma oscillation by incidence and the interaction between Eu3+ and Ag particles occurred simultaneously. (C) 1999 Elsevier Science B.V. All rights reserved.