Amorphous 'hard carbon' and microcrystalline diamond films are being investigated and characterized using high-sensitivity and spatial-profiling Raman spectroscopy. The 'hard carbon' films have broad Raman spectra with no diamond line while higher quality diamond films show only a single sharp diamond line. Features in the Raman spectra of the amorphous 'hard carbon' films correlate with the rates of specific types of wear. Changes in the relative intensity of the Raman band near 1570 cm-1 (G-band) compared to the band near 1360 cm-1 (D-band) are related to the rate of abrasive wear. Shifts in the frequency of the G-band are related to the rate of tribochemical wear. The results are consistent with a structural model of amorphous carbon films in which small (< 20 angstrom) graphitic microcrystals comprised of sp2 bonded domains are cross-linked by sp3 carbon atoms. Profiles of Raman frequency and linewidth obtained from spatially resolved Raman spectroscopy across CVD-grown diamond thin films show that the Raman frequency and position are correlated in these films and that both change in regions of poorer film quality.

Date Published: 1 April 1991
PDF: 8 pages
Proc. SPIE 1437, Applied Spectroscopy in Material Science, (1 April 1991); doi: 10.1117/12.45148

Published in SPIE Proceedings Vol. 1437:
Applied Spectroscopy in Material Science
David D. Saperstein, Editor(s)