Ion-beam sputtering and nanostructures of noble metals

Using the technique of ion-beam sputtering on gold (Au) and silver (Ag) metal films, metal nanoclusters vis-à-vis nanostructure materials are synthesized on silica glass substrates. Analyses of Rutherford backscattering spectra of Ar+-ion irradiated films confirm the ion-beam sputtering of metal films. Exponential decrease of experimentally measured areal density of Au atoms with the increase of ion doses has been elucidated. Optical absorption spectroscopy results reveal the formation of metal nanoclusters on the glass substrates. Red shift of the surface-plasmon resonance position due to the sputtering induced size reduction of Au nanoclusters on the silica substrates has been explained. Size reduction in this case is further corroborated with the scanning electron microscopy results.