Core Exciton and Band Structure in LiF

Abstract

By applying yield spectroscopy we could confirm recent absorption measurements locating the onset of ${\mathrm{Li}}^{+}$ ${\mathrm{Li}}^{+} 1s$ transitions at 54 eV. From energy-distribution-curve measurements using 120-eV photons, the ${\mathrm{Li}}^{+}$ ${\mathrm{Li}}^{+} 1s$ separation from the top of the valence band is found to be 50.2 eV. Combining these numbers with the band gap (13.6 eV), we find an electron-hole interaction energy of 10 eV. This is discussed in the context of two the-oretical calculations of ${\epsilon }_2$ spectra.