Appearance of crystal-field splitting in 2p-resonant electron spectra of K + in ionic solids

Abstract

It is known that a well-developed spectator structure appears in the electron spectra of ionic potassium compounds when excited with photons at the K + 2p absorption region (295 – 310 eV). This structure is due to the Auger-resonant inelastic scattering process 2p 6 + hv → (2p 53d) → 3p 43d + e, in which the 2p-hole states (the absorption final states) serve as the intermediate states. Due to the circumstance that all the configurations which contain the 3d orbitals are subject to a crystal-field splitting in solids, an interesting interplay of different bands of the electron spectra may be observed if the photon energy resonates with different crystal-field components of the absorption spectrum. Experimentally some of the crystal-filed effects are known from the comparison with each others the different spectra of KCl (here the crystal-field splitting D is about 0.9 eV) and with KMnF 3 ( D ∼ 0.06 eV). We have performed theoretical calculations in which the crystal-field effects are inserted into the usual atomic Hartree-Fock procedure. The calculations reproduce well the high-kinetic-energy parts of the electron spectra.