Ion-beam mixing of metal-insulator multilayers: A promising technique for the formation of metallic nanophases

The presence of metallic nanoclusters in an insulating matrix leads to non-linear optical properties with potential applications in optoelectronics. Ion implantation is currently used to produce such a composite material with limitations inherent to the implantation process, particularly concerning the doped thickness and the homogeneity of the transformed layer. Here we show that high-energy ion-beam mixing can be applied as an alternative ion beam technique to form metallic nanoclusters without the drawbacks of direct ion implantation. Thin SiO₂-metal multilayers were irradiated at room temperature with MeV heavy ions in order to produce an homogeneous SiO₂ layer containing metallic nanoclusters over the whole sample thickness. The present works deals with the mechanism leading to the formation of metallic nanophases by ion-beam mixing.