STRUCTURAL-PROPERTIES OF GRANULAR BI-SIOX FILMS PREPARED BY LOW-ENERGY CLUSTER BEAM DEPOSITION

In this paper, we propose a new technique for the elaboration of size controlled nanoparticles embedded in a matrix: the low-energy cluster beam deposition (LECBD). Bi-SiOx nanocermets have been prepared by cod eposition of Bi neutral clusters and SiOx molecules. We present a stud y by transmission electron microscopy (TEM) of the structural properti es of these new cermets. The clusters are generated by the gas-aggrega tion technique in a thermal source which produces clusters with a low energy. Then, the incident clusters do not break at the impact on the surface and conserve their size and structure. Consequently, the cerme ts are composed of Bi nanograins with a size distribution comparable t o that of the free clusters, at low metallic concentrations. This resu lt has been obtained for three different size distributions of the fre e clusters showing that the LECBD technique allows the control of the size of the embedded particles in the nanometric range. Moreover, the size and the concentration of grains are independent at metallic conce ntrations below 10%. This result is very important for studying the in fluence of these two parameters on the physical properties of granular materials. (C) 1997 Elsevier Science S.A.