Can buckling account for the features seen in graphite's Raman spectra?

TL;DR

This paper investigates whether buckling of graphene sheets can explain the Raman spectral features of graphite, using symmetry analysis and spectral interpretation within a specific space group.

Contribution

It introduces the space group P6_3mc to interpret graphite's Raman spectra, emphasizing buckling as a key structural feature affecting spectral characteristics.

Findings

Buckling model explains many spectral features

First order spectral assignments align with previous studies

Symmetry analysis supports buckling as a plausible explanation

Abstract

Raman scattering data were collected on graphite monochromator. Spectra were interpreted in terms of the space group $P6_3mc$, a subgroup of space group $P6_3/mmc$. The latter has commonly been used for the interpretation of Raman scattering data. Space group $P6_3mc$ corresponds to the buckling of graphene sheets and is consistent with many spectral features. Both the first and second order scattering were considered. Many first order results (most notably the assignments of the band at 1350 and the peak at 1620 cm$^{-1}$) were found to agree with previous observations [Y. Kawashima and G. Katagiri, Phys. Rev. B \textbf{66}, 104109 (2002)] carried out on highly oriented pyrolytic graphite samples. To check the consistency of the model, symmetry analysis was applied to the second order spectra. Also a simple test for buckling model was done.