Chemical Reactions of C-Atoms with Nanodiamond and Diamond Surfaces

The deposition of carbon atoms on surfaces of: a) silicon substrate; b) ultra dispersion diamond (UDD) and natural diamond (110) after H-treatment (ND-H-t) has been studied in-situ by N(E) CKVV AES with x-ray excitation combined with C1s and valence band XPS techniques. The chemical state (Cd) of carbon atoms on the surfaces of ND-H-t is identical to that in UDD. According to the CKVV Auger spectra the Cd state is conditioned by -band different from that of graphite. The carbon atoms were prepared by decomposition of CH4 on W hot-filament at 2300 K. In case a) the carbon atoms formed a graphite-like structure. In case b) the CKVV Auger spectra did not show any modification of initial chemical state on UDD or ND-H-t surfaces up to about 4 monolayers. The results point to incorporation of carbon atoms into diamond structure.