Raman Spectrum of Graphite

TLDR

Raman spectroscopy has been applied to single crystals of graphite and related graphite materials. The intensity of the 1355 cm⁻¹ band, which arises from a breakdown of the k‑selection rule, is inversely proportional to crystallite size, allowing size estimation, and its frequency yields two in‑plane force constants. Single‑crystal graphite displays a single Raman line at 1575 cm⁻¹, whereas other graphite materials show an additional line at 1355 cm⁻¹.

Abstract

Raman spectra are reported from single crystals of graphite and other graphite materials. Single crystals of graphite show one single line at 1575 cm−1. For the other materials like stress-annealed pyrolitic graphite, commercial graphites, activated charcoal, lampblack, and vitreous carbon another line is detected at 1355 cm−1. The Raman intensity of this band is inversely proportional to the crystallite size and is caused by a breakdown of the k-selection rule. The intensity of this band allows an estimate of the crystallite size in the surface layer of any carbon sample. Two in-plane force constants are calculated from the frequencies.