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We report energy distributions of electrons emitted from Al surfaces under impact by 1 keV Ar+ and 1-5 keV Ne+ ions. The variation of the energy distributions with the angle of incidence is different for both ions and provides information on the mechanism responsible for electron emission. For Ar+ electron emission results mainly from Auger neutralization, while for Ne+ an important emission mechanism is the decay of plasmon excitations. We find a transition between surface and bulk plasmon excitations as the energy of the ion is increased.

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In this work, we present a study of growth and characterization of nanocomposites, based on multiwalled carbon nanotubes and metal nanoparticles (Al, Ag, Au, Co, Cu, Fe, Ni and Ti). We observe a very different behavior between noble and transitions metals. All the nanocomposites are characterized by a network of carbon nanotubes with randomly insertion of spherical metal particles with dimensions of about 100 nm (clearly visible in SEM images). In particular, in transition metal nanocomposites, each tube on sheet surface is covered by particles of about 40-50 nm and for all metals the XPS measurements indicate the absence of chemical bonds and the simply physisorption of nanoparticle on carbon nanotube buckypaper. Furthermore, the nanocomposites show very different properties respect to pure carbon nanotubes: they are hydrophobic, their roughness is about 50% smaller than carbon nanotube and they exhibit a strong visible photoluminescence, which is absent in pure nanotube.