Fullerenes, Nanotubes and Carbon Nanostructures

A multi-scale investigation of nanostructured carbon films has been performed by means of inelastic light scattering (Raman and Brillouin scattering). Carbon films with different nanoand mesostructure have been deposited from supersonic cluster beams in a low energy deposition regime by exploiting aerodynamic focusing effects. Acoustic phonon propagation in the porous amorphous structure, where disorder acts as a damping factor, is investigated by Brillouin scattering. Depending on the nanoand meso-structure, acoustic phonons can either propagate along the medium, which acts as an elastic continuum at the meso-scale (i.e., hundreds of nm), or turn to overdamped oscillations localized by the structural disorder. Nevertheless, we show that it is always possible to measure the elastic constants of thin and porous films, when other techniques (e.g., nano-indentation) become critical. At the nano-scale, Raman scattering measurements show the typical structure of an amorphous carbon, where the structural disorder is affected by the Address correspondence to C. S. Casari, NEMAS-Center for Nano Engineered Materials and surfaces, INFM-Dipartimento di Ingegneria Nucleare, Politecnico di Milano, Via Ponzio 34/3, Milano I–20133, Italy. Fax: 39-02-2399-6309; E-mail: [email protected] Fullerenes, Nanotubes, and Carbon Nanostructures, 13: 199–210, 2005 Copyright # Taylor & Francis, Inc. ISSN 1536-383X print/1536-4046 online DOI: 10.1081/FST-200039261