DAMAGE PROCESS IN ELECTRON-IRRADIATED GRAPHITE STUDIED BY TRANSMISSION ELECTRON-MICROSCOPY .2. ANALYSIS OF EXTENDED ENERGY-LOSS FINE-STRUCTURE OF HIGHLY ORIENTED PYROLYTIC-GRAPHITE

The change in local atomic configurations during electron irradiation was studied by the analysis of the extended energy-loss fine structure of a highly oriented pyrolytic graphite crystal. The spectral change obtained was interpreted in terms of the local distortion of the basal planes and the formation of alternative types of chemical bonding. Th e pi bonding in the basal planes was retained even after the complete halo pattern was observed in the electron diffraction. This indicates that the disordering within the basal planes first occurs without dest roying the layered structure, consistent with the preceding report. A model for the damage process in graphite is proposed.