The Ag content in Ag-As-S glasses can bve spatially modified by illumination ofvisible light. Optical and thermal studies demosntrate that the Ag-content modification is cuased by Ag^+ ionic migration from the dark to the iluminated region in a sample. The migration can be reversed by changeing the illuminated region. The magnitude of the Ag-content modification is maximal (7 at. %) at a composition of Ag//25As//25S//50. The migration mechanism can be accounted for by assuming diffusion of photoexcited holes, and the composition dependence can be understood on the basis of the Owens’ thermodynamic model.
Norimitsu Yoshida Keiji Tanaka