Fabrication of hollow nanoclusters by ion implantation

Ag ions with four kinds of energies were implanted into silica to doses of 5 × 1016 and 1 × 1017 ions/cm2, respectively. Hollow Ag nanoclusters were observed in the 1 × 1017 Ag+ ions/cm2 implanted samples with energies of 150 and 200 keV. The evolution of hollow nanoclusters during annealing was carried out by in situ transmission electron microscopy observation. The energy dependence for the formation of hollow nanoclusters is studied. A potential mechanism for the formation of irradiation-induced nanovoids in nanoclusters is discussed.