Morphology and electronic structure of nanostructured carbon films embedding transition metal nanoparticles

Inclusions of metals in the growth process of carboncluster assembled materials (ns-C) induce modifications in thestructural and electronic properties of the material. A novelpulsed microplasma cluster source (PMCS) is able to deliverhighly intense, collimated and stable beams suitable forproducing bulk quantities of cluster-assembled nanocompositefilms. Loading of metal nanoparticles into carbon cluster basedfilms is obtained either by mixing a gas phase metallorganiccompound with the carrier gas (He) before entering into thesource (for example molybdenum (V) isopropoxide), or by using adouble component sputtering target (metal (Ti, Ni)/graphite). The study of filmmorphology on nanometer scale, carried out by transmissionelectron microscopy (TEM), reveals the dispersion in a ns-Cmatrix of metallic particles and, in the case of molybdenumcontaining films, also of carbide particles. Spatially resolvedultraviolet photoemission spectroscopy confirms the segregationof metal particles and exhibits evident anisotropy in theMo:ns-C films, mainly ascribable to the formation of carbidenanoparticles.