Neutron reflectivity analysis of Ni nanoclusters in sequentially ion implanted fused silica glass

Ion implantation is a useful technique to obtain composite materials such as metal nanocluster composite glasses (MNCGs), formed by nanometer-size metallic clusters embedded in silicate glasses. Due to quantum and dielectric confinement effects, these composites exhibit several effects such as an enhanced optical Kerr susceptibility, which can be important for application in all-optical switching devices. Moreover, MNCGs obtained by ion implantation of transition elements are important for their magnetic properties itself. Neutron reflectometry was used as a non-destructive method to determine the in-depth metal cluster density distribution and to roughly estimate the cluster size. The data analysis under a multi-layer sample approximation gives realistic results: this suggests the possibility to use neutron beams to study very diluted systems such as MNCGs.