Redetermination of the Dielectric Function of Graphite

The dielectric functions ϵ | arid ϵ ⟂ of graphite were redetermined by electron energy loss spectroscopy. At 11 eV a strong maximum in Im (ϵ | )is obtained, which is in accordance with earlier electron energy loss experiments, but in disagreement with recent reflectance measurements. A detailed discussion of uncertainties in the energy loss function Im(‐ 1/ϵ | ) and in the Kramers‐Kronig analysisconfirms, that the 11 eV‐maximum of Im (ϵ | ) is established beyond experimental error. Our ϵ | data are in agreement with earlier electron energy loss and optical results.