Empty electronic states of silver as measured by inverse photoemission

Abstract
We have performed inverse photoemission (bremsstrahlung isochromat spectroscopy) at hν=9.7 eV on polycrystalline silver. Our spectrum can be related to the calculated density of unoccupied states up to 7 eV above the Fermi level EF. Pronounced features in the isochromat spectrum are associated with critical points in the band structure of silver. We find X6 at EF+(2.1±0.1) eV and L4+ at EF+(3.77±0.09) eV. The results are compared with band-structure calculations as well as other experimental findings.