Infrared Spectra of Explosion Nanodiamonds: A Comparison with Spectra of Hydrogenated Amorphous Carbon Films

Abstract

We report infrared absorption spectra of explosion nanodiamonds and compare these with spectra of a-C:H films prepared by laser ablation. Similarities between these spectra are discussed. In particular, we find that a feature near 1620 cm(-1) in nanodiamond particle spectra can be associated with the presence of C=C groups. This is supported by the observation of bands arising from CH2. We suggest that these groups are. created by surface reconstruction on these extremely small particles that tends to de-emphasize tetrahedral bonding in the surface layer.