How to obtain a reliable structural characterization of polished graphitized carbons by Raman microspectroscopy

Abstract

A series of graphitized carbon materials, produced by the pyrolysis of an anthracene-based coke at temperatures ranging from 1600 to 2900 • C, were studied by Raman microspectroscopy to assess the applicability of this technique to the particular case of polished carbon materials. The polishing process was shown to change significantly the first-order Raman spectra (D band intensity increase) and therefore to induce unacceptable errors in the characterization of the intrinsic structure of these materials. The deconvolution of Raman spectra, related to the unpolished graphitized carbons at varying temperatures, highlighted a linear relationship between the intensity ratio I D /I G and the G band width. Thus, as the latter appears to be insensitive to the polishing, we highly recommend using it for a reliable assessment of the intrinsic structural disorder of polished carbon materials.

Carbonaceous biosignatures of diverse chemotrophic microbial communities from chert nodules of the Ediacaran Doushantuo Formation

“…The Raman spectra were acquired using a 514 nm Arion laser with absolute laser power of 15-20 mW through a density filter (D = 0.3), an aperture hole of 100 lm in diameter, and a 100 Â objective with a final power of c. 2.5 mW in a 1-2 lm spot on the sample (measured with a Coherent Lasercheck Analyser). The laser beam was focused on the carbonaceous material underneath the polished surface of thin sections in order to avoid surface contamination and polishing artifacts (Beyssac et al, 2003;Ammar and Rouzaud, 2012). The Raman spectra were obtained in the range of 150-2000 cm À1 with the acquisition time of 2 Â 10 s. Some targeted areas were scanned on an XY stage with a spatial resolution of 1 lm per step in order to obtain data sets for generating twodimensional maps of Raman spectral parameters.…”

“…as a source of lm-scale structural heterogeneities. Lastly, as the Raman spectra were obtained by focusing the laser beam through the mineral onto organic matter in the subsurface, thinsection polishing artifacts (Beyssac et al, 2003;Ammar and Rouzaud, 2012;Maslova et al, 2012) cannot be the reason for the lm-scale structural heterogeneities.…”

Chemical Mapping and Electrochemical Performance of Manganese Dioxide/Activated Carbon Based Composite Electrode for Asymmetric Electrochemical Capacitor

“…[48][49][50] Fig . 5a shows the Raman spectra of pristine BP, which is characterized by the typical D (1334 cm −1 ) and G (1598 cm −1 ) bands.…”

“…46,47 At the same time, Raman spectroscopy has been proved to be a useful tool to study the vibrational properties and electronic structures of carbon materials. [48][49][50] Interestingly, information about the distribution or the physical properties * Electrochemical Society Student Member.…”

Raman spectroscopy for the investigation of carbon‐based black pigments

“…4) proved to be very similar to graphite as regards to band positions (G*, D1) and eventually showed a lower fluorescence background when single particles were measured, instead [49] to 1620 [44] D1 D A 1g [40,53,56] ; edge effects as oxides or C¼C bonds [37,51] ; in plane defects and heteroatoms [43,45,54,64] ; sp 3 -sp 2 carbon bonds [8] ; volatile compounds, polyenes and ions [33] From 1301 to 1317 (for a NIR/IR excitation [47,51,58] ) to 1390 [49] D2 D′, G2 E′ 2g or E 2g or oxidized sp 2 carbons [37] ; non sandwiched graphene layers [51] ; defects as imperfect graphite or disordered E 2g [33,45,53,64] ; splitting of degenerated E 2g [41] ; E 1u [56] From 1599 [51] to 1635 [15,16,33,37,38,43,45,50,[53][54][55][56][64][65][66][67][68][69] …”