Fig. 5: Scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS) of an ion track in diamond.
The sample was irradiated with 9 MeV C602+ ions at a fluence of 5.0 × 1010 C60 cm−2. a A STEM image of ion tracks observed under conditions optimized for EELS measurements but not for STEM. The purpose of this low-quality image a is to indicate that the location of the line-scanning of STEM-EELS was performed along a green line. b EELS spectra at the C 1s edge. Blue and red spectra at the bottom are literature data of graphite and diamond, respectively32. Upper spectra were experimentally measured at various distances x from the center of the track. Each spectrum was fitted by Eq. (2) as the sum of the standard spectra of graphite and diamond32 with optimizing the graphite ratio y. The optimized curves are shown by thin black curves. The π* peak was indicated by a vertical broken line. c The intensity of the π* peak and the optimized graphite ratio y are plotted along the distance from the center of the track. A horizontal broken line is a guide for the eye.
