On the characterization of disordered and heterogeneous carbonaceous materials by Raman spectroscopy

The relationship between micro-Raman spectral parameters and reflectance of solid bitumen

“…For each sample five individual bitumen particles were measured. Curve fitting for the determination of spectral parameters was performed with the GaussLorentz model in the instrument software, and all the analytical and calculation procedures were conducted following Beyssac et al (2003).…”

“…Previous studies have also discussed the influence of factors except maturity on the Raman spectral parameters of solid organic matter, including their precursors (Quirico et al, 2009), fluids (Guedes et al, 2005), measurement conditions (laser wavelength, excitation time), sample preparation (powder sample or polished thin section sample), and models and procedures for curve fitting (Beyssac et al, 2003;Quirico et al, 2005). These factors affect the magnitude of Raman spectral parameters of solid organic matter, accounting for poor agreement among results from different authors.…”

“…The D band is also called D1 band (Marques et al, 2009;Wopenka and Pasteris, 1993) or A band (Kelemen and Fang, 2001), and it originates in vibrations of the disordered structure of carbonaceous material (Beyssac et al, 2002(Beyssac et al, , 2003. The G band is assigned to vibrations of the ordered (graphitic) structure (Beyssac et al, 2002(Beyssac et al, , 2003. With increasing thermal maturity, these two bands show regular changes in their position, FWHM (full width at half maximum) and intensity, which have been shown to be clearly correlated with maturity (Guedes et al, 2010;Kelemen and Fang, 2001;Kostova et al, 2012;Quirico et al, 2005).…”

“…The first-order characteristic bands of the Raman spectrum of carbon in coals have been found to generally occur at approximately 1350 cm −1 (D band) and 1580 cm −1 (G band) (Guedes et al, 2010;Kwiecinska et al, 2010;Wopenka and Pasteris, 1993). The D band is also called D1 band (Marques et al, 2009;Wopenka and Pasteris, 1993) or A band (Kelemen and Fang, 2001), and it originates in vibrations of the disordered structure of carbonaceous material (Beyssac et al, 2002(Beyssac et al, , 2003. The G band is assigned to vibrations of the ordered (graphitic) structure (Beyssac et al, 2002(Beyssac et al, , 2003.…”

Potential Raman parameters to assess the thermal evolution of kerogens from different pyrolysis experiments

“…Kelemen et al [12] and Liu et al [13] proposed a positive linear correlation between the inter-interval of peaks D/G and Ro. Beyssac et al [14,15] and Bernard et al [16] suggested that simple D/G band ratios are not adequate to evaluate the thermal maturity level of geologic carbonaceous materials by changes in Raman spectra. It seems that Raman spectra could be applied to evaluate the thermal maturity of carbonaceous materials, but that different reports have contradictory results and perspectives on the usefulness of different parameters.…”