X-ray photoelectron spectroscopy study on gold nanoparticles supported on diamond

By exploiting the self-organization of metal salt-loaded diblock copolymer micelles followed by a plasma-induced removal of the polymer matrix, well-separated gold particles ranging in size from 1.6 to 10 nm have been prepared on top of diamond substrates. X-ray-induced photoelectron spectra of the valence-band region demonstrate that the electronic properties of such nanoparticles essentially reflect the metallic behavior of the bulk material as can be inferred from the evolution of the d-band shape and the finite density of states at the Fermi energy. This experimentally extends the lower limit for the metallic state of supported Au particles down to a diameter of 1.6 nm.