Buckyball microwave plasmas: Fragmentation and diamond-film growth
Microwave discharges (2.45 GHz) have been generated in C{sub 60}-containing Ar produced by flowing Ar over fullerene-containing soot. Optical spectroscopy shows that the spectrum is dominated by the d{sup 3}{Pi}g-a{sup 3}{Pi}u Swan bands of C{sub 2} and particularly the {Delta}v = {minus}2, {minus}1, 0, +1, and +2 sequences. These results give direct evidence that C{sub 2} is one of the products of C{sub 60} fragmentation brought about, at least in part, by collisionally induced dissociation (CID). C{sub 60} has been used as a precursor in a plasma-enhanced chemical vapor deposition (PECVD) experiment to grow diamond-thin films. The films, grown in an Ar/H{sub 2} gas mixture (0.14% carbon content, 100 Torr, 20 sccm Ar, 4 sccm H{sub 2}, 1500 W, 850{degree}C substrate temperature), were characterized with SEM, XRD, and Raman spectroscopy. Growth rate was found to be {approx} 0.6 {mu}/hr. Assuming a linear dependence on carbon concentration, a growth rate at least six times higher than commonly observed using methane as a precursor, would be predicted at a carbon content of 1% based on C{sub 60}. Energetic and mechanistic arguments are advanced to rationalize this result based on C{sub 2} as the growth species.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 10104979
- Report Number(s):
- ANL/CHM/PP-80544; ON: DE94003209; TRN: 94:000789
- Resource Relation:
- Other Information: PBD: Aug 1993
- Country of Publication:
- United States
- Language:
- English
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