Sputtering of nanodispersed targets of gold and desorption of gold nanoclusters (2–100 nm) by 6 MeV Au5 cluster ions

The first experiment on sputtering of nanodispersed targets of gold (size range of grains is 2-100 nm) by cluster ions Au-5(+)(1.2 MeWat., Sigma(dE/dx)(n) = 49 keV/nm, Sigma(dE/dx)(e) = 11 keV/nm) is reported. The matter sputtered/desorbed from the targets was gathered on collectors. The total amount of gold regardless of the type of sputtered/desorbed particles was measured by neutron activation analysis. Desorption of gold nanoclusters was registered by TEM. It is shown that the total yield of the ejected matter increases from 1.3 x 10(4) to 3.5 x 10(4) at./projectile with mean grain size increase from 4.5 to 56 nm. For all the targets a substantial fraction of gold is ejected in the form of nanoclusters sized within the same size range as that of the grains on the targets. Size distributions of desorbed clusters are systematically shifted towards smaller sizes by comparison with the grain size distributions on the targets. Desorption of the clusters with sizes up to 80 nm was observed for the first time. Results are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.