Graphite: Electronic and structural properties studied by electron-energy-loss and secondary-electron-emission spectroscopy

The carbon K-edge measurement by high-resolution electron-energy-loss spectroscopy is reported and compared with secondary-electron-emission spectra. A very good correlation has been found between the two techniques, which gives a complementary view of the final density of states. The comparison of the results allows identification of the onset of the extended x-ray absorption fine-structure regime. From the fine structure above the K edge we obtain radial distribution functions which are sensitive to the momentum-transfer direction. This is explained by the orientational dependence of the polarization selection rules, in the dipole approximation, from a 1s→π or 1s→σ conduction-band state.