Raman spectra of graphite edge planes

The Raman spectrum of the graphite edge plane is different from that of the cleaved basal plane because the 1355 cm−1 and 1620 cm−1 bands are clearly observed. These spectral features of the edge plane have been interpreted to be due to the structural imperfection caused by polishing. In the present work, the Raman spectra of the edge planes prepared by various methods were systematically studied. As a result, it was concluded that the observed spectral features of an edge plane were mainly due to the discontinuity of graphite planes that inevitably exists at the edge. It was also demonstrated that either the degree of graphitization or the orientation of graphite planes can be evaluated by the Raman spectra of graphite materials. These findings were applied to the characterization of the radial heterogeneity of a graphite fiber and the interfacial analysis of a carbon-carbon (C/C) composite.