DIAMOND AND DIAMOND FILMS STUDIED BY RAMAN-SPECTROSCOPY

The structure of cubic, hexagonal diamonds and diamond like films are analyzed by comparison of their Raman spectra to those of other carbon structures including fullerenes C60 and C70. Two kinds of ''diamond films'' are found. One of them has the cubic diamond structure, with nevertheless a slight compressive distorsion which can be evaluated from the increase in frequency and band-width of the C-C stretching mode. The second series of films have a new structure named ''diamite ''presenting a pseudo-hexagonal network, similar to that of graphite but with longer C-C bonds in the ''layer'' and having inter-layer C-C bonds.