Origin of the D line in the Raman spectrum of graphite: A study based on Raman frequencies and intensities of polycyclic aromatic hydrocarbon molecules

Abstract

A common valence force field for polycyclic aromatic hydrocarbons (PAHs) and graphite has been used in order to explain their Raman spectra from a unified viewpoint. On this basis the correlation observed between experimental spectra has been explained and rationalized. Quantum chemical density functional theory calculations of Raman intensities of small PAHs have been also performed, supporting the conclusions obtained from the dynamical analysis. The results obtained are useful for the characterization of materials containing graphitic domains and provide some new insight on the nature of the D peak in disordered graphite.

Assessment of Thermal Maturity Trends in Devonian–Mississippian Source Rocks Using Raman Spectroscopy: Limitations of Peak-Fitting Method

“…dependent. These G-band peak positions agree with frequencies tabulated in the literature (Table 6) (Wang et al, 1990;Spotl et al, 1998;Matthews et al, 1999;Castiglioni et al, 2001;Beyssac et al, 2002;Quirico et al, 2005;Guedes et al, 2012;Lünsdorf et al, 2014;Li et al, 2015;Lünsdorf, 2016); however, using only one peak to fit the D-band resulted in a shift in the peak maximum location, as shown in Table 2. Limiting the fit to two peaks permitted the bands to be evaluated as a whole, without over-complicating the analysis, and also without needing to add further peaks when the true number of vibrational modes that contribute to the spectral region between ~1,200 and 1,500 cm −1 is unknown.…”

“…While a two-peak fit elucidated some basic correlations with VRo, it was apparent that additional peaks comprised the spectra, both from the experimental data and the literature (Wang et al, 1990;Matthews et al, 1999;Castiglioni et al, 2001;Beyssac et al, 2002;Jehlička et al, 2003;Quirico et al, 2005;Guedes et al, 2010Guedes et al, , 2012Lünsdorf et al, 2014;Li et al, 2015;Lünsdorf, 2016). Additional peaks were added to the fitting process and were centered between 1,263 and 1,286 cm −1 and 1,430 and 1,466 cm −1 , depending on the sample.…”

“…Raman spectra of shale reveal two characteristic peaks: the disordered, D-or D1-band, and the graphitic, or G-band (Wang et al, 1990). These features arise near ~1,310-1,370 and ~1,580-1,610 cm −1 , respectively; however, the exact frequency is dependent on the sample and the spectral acquisition parameters (Wang et al, 1990;Spotl et al, 1998;Matthews et al, 1999;Castiglioni et al, 2001;Beyssac et al, 2002;Quirico et al, 2005;Guedes et al, 2012;Lünsdorf et al, 2014;Li et al, 2015;Lünsdorf, 2016). Other D-vibrational modes have been characterized and are referred to as D2 (~1,620 cm −1 ), D3 (~1,500 cm −1 ), and D4 (~1,250 cm −1 ).…”

“…Again, these vibrational modes depend on the sample. While several studies have investigated the origin of the D-band (Wang et al, 1990;Matthews et al, 1999;Castiglioni et al, 2001), the G-band has been unambiguously assigned to aromatic ring breathing modes.…”

Infrared and Raman Vibrational Spectroscopies Reveal the Palette of Frescos Found in the Medieval Monastery of Karaach Teke

“…Carbon has high Raman cross-section and thus can easily be identified by this specific vibrational spectroscopy. The quality of carbon structure can also be justified 19 . For example in the µ-Raman spectrum of 9the black layer of sample K8-B (figure 8), graphite and not the typical amorphous Carbon black is the dominant carbon structure.…”