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 (H2Ar) atmosphere, annealing in oxidizing (air) atmosphere is the most effective in promoting cluster formation above 700800°C due to a thermally activated correlated diffusion of gold atoms and excess oxygen molecules coming from the atmosphere.