Spectral Momentum Density of Amorphous Carbon from (e,2e) Spectroscopy

The spectral momentum density of the valence band of an amorphous carbon film has been measured by ($e$, $2e$) spectroscopy. Two "bands," energy as a function of momentum, are resolved. One extends from 23 eV below the Fermi energy to about 10 eV below $E_{\mathrm{F}}$. The other, ∼ 9 eV below $E_{\mathrm{F}}$, does not disperse significantly. Although the existence of diamond bonding in the film cannot be ruled out, the bands are more suggestive of the graphite band structure.