Accession Number:

ADP012162

Title:

A Model to Interpret the Raman Spectra of Disordered, Amorphous and Nanostructured Carbons

Descriptive Note:

Proceedings

Corporate Author:

CAMBRIDGE UNIV (UNITED KINGDOM) DEPT OF ENGINEERING

Personal Author(s):

Report Date:

2001-04-01

Pagination or Media Count:

12.0

Abstract:

Raman spectroscopy is a very popular, non-destructive tool for the structural characterization of carbons. Raman scattering from carbons is always a resonant process, in which those configurations whose band gaps match the excitation energy are preferentially excited. The Raman spectra of carbons do not follow the vibration density of states, but consist of three basic features, the G and D peaks around 1600 and 1350 cmexp-1 and an extra T peak, for UV excitation, at 980-1060 cmexp-1. The Raman spectra at any wavelength depend on 1 clustering of the spexp2 phase, 2 bond length and bond angle disorder, 3 presence of spexp2 rings or chains, and 4 the spexp2spexp3 ratio. It will be shown how the basic features of the Raman spectra vary by rationalizing them within a three-stage model of order of carbons. It is shown how the three-stage model can account for the vast range of experimental data available for Raman experiments at any excitation wavelength. This model can also account for apparently contradictory trends reported in literature, since the clustering of the spexp2 phase and the spexp3 to spexp2 conversion are separately treated.

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE