Small silver particles in photosensitive glass: Their nucleation and growth

Nucleation and growth kinetics of Ag particles in glass have been investigated by means of optical spectroscopy. The underlying purpose of the work is production of particles for quantum size experiments smaller than previously available. Ag^o centers are produced by UV irradiation, and some ‰ of them act as nuclei. The particles grow at elevated temperatures by diffusion, and two growth mechanisms were identified. First, the Ag^o centers coagulate at the nuclei, forming particles of some hundred atoms. Samples with markedly smaller particles and narrow size distributions could not be produced because of the high growth velocity. Subsequently, the growth is continued much slower, by diffusion of Ag⁺, the kinetics following the growth theory of Ham.