Cluster-Assembled Nanocomposites: Functional Properties by Design

The unique functional properties of nanocomposites meet many of the material requirements sought after in numerous applications of today's high-tech industry. This, in turn, inspires material scientists to devise new methods that can further expand the palette of available nanocomposites. Precise control over the chemistry, morphology, and microstructure of nanocomposites' constituents promises the eventual ability to design any composite material for any specific requirement. However, today's synthesis methods still lack the ability to simultaneously control all chemical, morphological, and microstructural features of nanocomposites in a one-step process. Here, an alternative approach to fabricate fully tailorable nanocomposites under well-defined conditions is described. In particular, this progress report focuses on the combination of cluster ion beam and thin-film deposition technologies to fabricate cluster-assembled nanocomposites via codeposition of cluster ions and matrix materials. Emphasis is given to the state-of-the-art cluster deposition system, designed and built by our research group, as well as to its unique abilities. Moreover, case studies on two cluster-assembled nanocomposite material systems (Fe/Ag_m and Fe/Cr_m ) prepared with this method are presented. Finally, an outlook on research directions for cluster-assembled nanocomposites is discussed.