Raman Spectroscopy for Quantitative Analysis of Point Defects and Defect Clusters in Irradiated Graphite
Figure 6
Peak width of 1580 cm−1 versus intensity ration of for HOPG foils irradiated with 25 keV He+ at temperatures ranging from RT to 973 K. Open, half-closed, and closed symbols, respectively, correspond to the appearance of the TEM diffraction patterns of s (spot), hs (halo and spot), and h (halo). The in-plane crystalline size La calculated by Tuinstra and Koenig’s relation [34] is also indicated in the figure. The calculated La, especially for the data along the solid line, should not be attributed to the in-plane crystalline size but to the phonon correlation length broken by in-plane defects of vacancies, as described in the text.
