Clustering of gold atoms in ion-implanted silica after thermal annealing in different atmospheres

Abstract

The clustering process of gold atoms in ion-implanted silica, during annealing in different atmospheres, is experimentally investigated and phenomenologically described. With respect to inert (Ar) or reducing ${(H}_{2}\ensuremath{-}\mathrm{Ar})$ atmosphere, annealing in oxidizing (air) atmosphere is the most effective in promoting cluster formation above $700--800\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ due to a thermally activated correlated diffusion of gold atoms and excess oxygen molecules coming from the atmosphere.