Fabrication of hollow Ag nanoclusters in silica by irradiation with Ar ions

Ion irradiation is an effective method to control the morphology, size and distribution of metal nanoclusters in substrates. In this work, Ag nanoclusters embedded in silica by 200 keV Ag+ ion implantation were irradiated at room temperature with Ar+ ions at 200 keV and 500 keV to different fluences. After irradiation, a transmission electron microscopy (TEM) study revealed that nanovoids are formed in the larger Ag nanoclusters. With the increase of fluence and energy of the Ar+ ions, the number and average size of the nanovoids grow combining with increases in the average size of the larger Ag nanoclusters within a projected range. During the ion irradiation process, the electronic energy and nuclear energy loss of the Ar+ ions determine the size of the hollow Ag nanoclusters and the change of the size and distribution of Ag nanoclusters in silica, leading to changes in the optical absorption spectra.