PLASTIC-FLOW INDUCED BY SINGLE-ION IMPACTS ON GOLD

The formation of holes in thin gold foils as a result of single ion im pacts by 200 keV Xe ions has been followed using transmission electron microscopy. Video recording provided details of microstructure evolut ion with a time resolution of 1/30th sec. Hole formation involves the movement by plastic flow of massive amounts of material, on the order of tms of thousands of Au atoms per ion impact. Plastic Row, as a cons equence of individual ion impacts, results in a filling of both holes and craters as well as a thickening of the gold foil. Change in morpho logy during irradiation is attributed to a localized, thermal-spike in duced melting, coupled with plastic flow under the influence of surfac e forces.