13C NMR spectroscopy of amorphous hydrogenated carbon and amorphous hydrogenated boron carbide
Abstract
We report the 13C NMR spectrum of amorphous hydrogenated carbon and boron carbide. The amorphous hydrogenated carbon spectra consist primarily of an sp3 line at 40 ppm and an sp2 line at 140 ppm and are in reasonable agreement with the recent theoretical calculations of Mauri, Pfrommer, and Louie, but there are some notable discrepancies. The amorphous hydrogenated boron carbide spectra are very different from those of amorphous hydrogenated carbon, being dominated by one line at 15 ppm. We interpret this line as due to carbon bound in boron carbide icosahedra, because polycrystalline boron carbide with boron carbide icosahedra as the unit cell gives very similar NMR spectra.
- Publication:
-
Physical Review B
- Pub Date:
- April 1999
- DOI:
- 10.1103/PhysRevB.59.9745
- Bibcode:
- 1999PhRvB..59.9745B
- Keywords:
-
- 76.60.-k;
- 82.80.Ch;
- 81.15.Kk;
- Nuclear magnetic resonance and relaxation;
- Vapor phase epitaxy;
- growth from vapor phase