Structural and optical properties of co-sputtering synthesized Au-Cu alloy nanoclusters in silica

Silica films containing metal nanoclusters (NCs) exhibit peculiar optical properties that have made them attractive in several application fields. As an example, metal quantum dot composite glasses exhibit an enhanced optical Kerr susceptibility, i.e. the most important physical process for applications in all-optical switching devices [1]. In this work, (copper+gold)-containing silica films were synthesized by radiofrequency co-sputtering deposition technique. The alloy composition can be varied from pure Au to pure Cu to investigate the alloy nanostructure as a function of the composition. Structural and compositional characterization of the samples was performed by Rutherford backscattering spectrometry (RBS), X-ray diffraction (GIXRD), extended x-ray absorption fine structure (EXAFS), optical absorption spectroscopy and Zscan analysis.