Abstract
The complex dielectric constant and associated functions are derived by application of the Kramers-Kronig relation to reflectance data for graphite obtained in the energy range to 26 eV. It is possible to divide the optical properties into two spectral regions. In the range 0 to 9 eV, intra- and interband transitions involve mainly the bands. At higher energies, a broad absorption peak near 15 eV is associated with interband transitions involving the 3 electrons per atom. This viewpoint is strongly supported by evaluation of the sum rules for . Plasma resonances which produce peaks in the energy-loss function at 7 and 25 eV are identified and described physically. At low energies, structure in the reflectance curve near 0.8 eV is attributed to the onset of transitions between the and bands at the point . This yields a value for of ≈0.4 eV.
- Received 2 November 1964
DOI:https://doi.org/10.1103/PhysRev.138.A197
©1965 American Physical Society