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 lending to the formation of metallic nanophases by ion-beam mixing.