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The electrical properties of cluster-assembled nanostructured palladium oxide $({\text{ns-PdO}}_{x})$ thin films grown by supersonic cluster beam deposition have been characterized by means of a customized ac current-sensing atomic force microscope. Scanning impedance microscopy is shown to provide a deep picture of the electrical properties of thin nanostructured interfaces even in the case of very soft and poorly adherent films. In particular, the dielectric constant of ${\text{ns-PdO}}_{x}$ can be quantitatively determined as well as its $I\text{\ensuremath{-}}V$ characteristics. Moreover, the measurement of the tip-sample parasitic capacitance can be exploited to probe the overall mesoscale conductive character of thin films and to give a complementary and more precise view of the oxidation of ${\text{ns-PdO}}_{x}$ obtained by x-ray photoemission spectroscopy.

Amorphous carbon films with $sp\text{\ensuremath{-}}s{p}^{2}$ hybridization, produced by supersonic cluster beam deposition, shows the presence of both polyynic and cumulenic species [L. Ravagnan et al., Phys. Rev. Lett. 98, 216103 (2007)]. Here, we present an in situ Raman characterization of the low-frequency vibrational region $(400\char21{}800\text{ }{\text{cm}}^{\ensuremath{-}1})$ of $sp\text{\ensuremath{-}}s{p}^{2}$ films at different temperatures. We report the presence of two peaks at 450 and $720\text{ }{\text{cm}}^{\ensuremath{-}1}$. The lower frequency peak shows an evolution with the variation of the $sp$ content and it can be attributed, with the support of density functional theory simulations, to bending modes of $sp$ linear structures. The peak at $720\text{ }{\text{cm}}^{\ensuremath{-}1}$ does not vary with the $sp$ content and it can be attributed to a feature in the vibrational density of states activated by the disorder of the $s{p}^{2}$ phase.

Nanostructured carbon films consisting of sp chains (polyynes and polycumulenes) embedded in an sp 2 matrix are grown using supersonic carbon cluster beam deposition in ultrahigh vacuum at room temperature. All the specimens have been analyzed by in situ Raman spectroscopy. The use of different excitation wavelengths (532 and 632.8 nm) confirms the presence of distinct carbynoid species. Chemical stability of the sp species has been studied by exposing the as-deposited films to 500 mbar of H 2 , He, N 2 , and dry air. Gas exposure produces an exponential decay of the carbynoid fraction slightly affecting the sp 2 component. Helium, hydrogen, and nitrogen do not chemically interact with the sp chains whereas oxygen reacts with the carbynoids species causing their fast and almost complete destruction. The films have been also thermally annealed at 20°, 100°, 150°, and 200°C. The amount of carbynoid species is rapidly and strongly reduced at temperature larger than room temperature. The relevance for material science and interstellar chemistry of the production of a bulk form of carbon where sp and sp 2 hybridizations coexist is addressed.

Supersonic cluster beam deposition (SCBD) has proved to be a powerful technique for assembling nanostructured materials with tailored physicochemical properties. Here we report a series of spectroscopic investigations of the growth process, from the early stages up to thick layers, of carbon films obtained by the deposition of carbon clusters. In order to perform the characterization in situ we have used an ultrahigh vacuum SCBD apparatus directly connected with an electron spectrometer. Carbon clusters have been deposited on Ag(100) and $\mathrm{Si}(100)\ensuremath{-}(2\ifmmode\times\else\texttimes\fi{}1)$ surfaces. The electronic structure of the thus-obtained samples has been studied via valence-band and core-level photoemission. Multielectron excitations were studied by means of electron energy-loss spectroscopy. Thermal annealing of nanostructured carbon films predeposited onto the Si(100) surface promotes the formation of a SiC-like film. This process initiates at temperatures lower than those observed when closed-cage fullerene precursors are used.