Double implantation in silica glass for metal cluster composite formation:a study by synchrotron radiation techniques

Silica glass containing metal clusters is studied for both basic and applie d aspects, related to the physics of cluster formation and to the optical p roperties of these materials. To obtain such composite structure, Cu+ Ni, A u+ Cu, Au+ Ag, Cu+ Co, and Cu+ Ag sequential implantations in fused silica were realized. The resulting systems, after possible annealing in various a tmospheres, were studied by synchrotron radiation-based techniques, namely, extended X-ray absorption fine structure (EXAFS) spectroscopy, grazing inc idence X-ray diffraction (GIXRD), and grazing incidence small angle X-ray s cattering (GISAXS). The unique potential of these techniques is the capabil ity to investigate dilute (volume fraction of clusters greater than or equa l to 0.01) and very thin (50 nm) systems. In the presented experiment, both pure and alloy clusters in the nanometer range of size were observed to fo rm, pointing out the complexity of the cluster formation process in terms o f physical and chemical driving forces. (C) 2001 Elsevier Science B.V. All rights reserved.