Nanocluster formation during ion irradiation of SiO2/Ag/SiO2 multilayers

Nanocluster formation during heavy ion bombardment of a thin contiguous Ag layer sandwiched between two continuous SiO2 layers has been observed using in situ transmisssion electron microscopy (TEM). During ion bom bardment, irradiation-induced plastic flow of the Ag film enlarges pre-existing pin h oles and separates the film at grain boundaries transforming the as-deposit ed thin Ag film into three-dimensional microcrystals having diameters great er than 30 nm. This plastic flow process is similar to that observed in fre e-standing Ag specimens during heavy ion irradiation. In addition to plasti c flow, ballistic recoils inject Ag atoms into the SiO2 where they precipit ate into nanoclusters. Both effects are greatly enhanced by simultaneous el ectron and ion irradiation. (C) 2001 Published by Elsevier Science B.V.