Origin of the 1150-cm-1 Raman mode in nanocrystalline diamond
Abstract
The peak near 1150 cm-1 in the visible Raman spectra of poor quality chemical-vapor-deposited diamond is often used as the signature of nanocrystalline diamond. We argue that this peak should not be assigned to nanocrystalline diamond or other sp3-bonded phases. Its wave number disperses with excitation energy, its intensity decreases with increasing excitation energy, and it is always accompanied by another peak near 1450 cm-1, which acts similarly. This behavior is that expected for sp2-bonded configurations, with their smaller band gap. The peaks are assigned to transpolyacetylene segments at grain boundaries and surfaces.
- Publication:
-
Physical Review B
- Pub Date:
- March 2001
- DOI:
- 10.1103/PhysRevB.63.121405
- Bibcode:
- 2001PhRvB..63l1405F
- Keywords:
-
- 78.30.Ly;
- 61.43.Dq;
- 63.50.+x;
- 81.05.Tp;
- Disordered solids;
- Amorphous semiconductors metals and alloys;
- Vibrational states in disordered systems;
- Fullerenes and related materials