Fabrication and characterization of Au/SiO2 nanocomposite films grown by radio-frequency cosputtering

Au/SiO2 nanocomposite films were prepared on Si wafers by cosputtering of SiO2 and gold wires. Au/Si atomic ratios in Au/SiO2 nanocomposite films were varied from 0.53 to 0.92 by controlling the length of gold wire to study the evolution of the crystallization of gold, the size of Au/SiO2 nanocomposite particles, and the optical properties of as-deposited Au/SiO2 nanocomposite films. An X-ray photoelectron spectroscopy reveals that Au exists as a metallic phase in the bulk of SiO2 matrix. Dome-shaped Au/SiO2 nanocomposite particles and both Au (1 1 1) and (2 0 0) planes were observed in a field-emission scanning electron microscopy and X-ray diffraction studies respectively. With an ultraviolet-visible, absorption peaks of Au/SiO2 nanocomposite films were observed at 525 nm.