UPS and XPS spectra of CdF2and SrF2and interpretation of optical properties of these compounds

Abstract
The authors have carried out UPS and XPS measurements of CdF2 and SrF2 crystals from which they have obtained information about the density of states distribution and energy position of filled states. The photoemission results associated with optical measurements are compared with recent theoretical band structure models. This study shows an agreement between the authors' experimental results and band structure calculations for the upper part of the valence band (F-2p states) but it disagrees in the position of the first core levels.