Inverse photoemission from polycrystalline samples

A three-step model for inverse photoemission (bremsstrahlung spectroscopy) is developed in analogy to the well known corresponding model for photoemission. It is shown under which conditions bremsstrahlung spectra measure the density of the final state above the Fermi level. Data on polycrystalline nickel can be interpreted consistently when contributions due to indirect (k non-conserving) radiative transitions are taken into account as well as direct (k-conserving) transitions. © 1984.