Au-Cu alloy nanocluster doped SiO2 films by sol-gel processing

Au-Cu alloy nanocluster formation in silica films has been achieved in the present study by sol-gel processing. A fundamental role for obtaining alloy clusters instead of separation of the metallic species is played by the annealing atmosphere. Annealing in reducing atmosphere (hydrogen-containing) results in Au-Cu alloy formation, whereas air annealing promotes not only Au cluster precipitation and Cu oxidation but also Au-Cu alloy separation in samples previously annealed under reducing atmosphere.