Autoionization phenomena involving the 2p53dconfiguration of argonlike ions in ionic solids

The photon-induced Auger and photoelectron spectra of the argonlike ions ${\mathrm{Cl}}^{\mathrm{-}}$ (in NaCl), ${\mathrm{K}}^{+}$ (in KCl), ${\mathrm{Ca}}^{2+}$ (in ${\mathrm{CaCl}}_2$ and ${\mathrm{CaF}}_2$), and ${\mathrm{Sc}}^{3+}$ (in ${\mathrm{Sc}}_2$ ${\mathrm{O}}_3$) have been measured in the vicinity of the ${\mathit{L}}_{23}$ absorption edges of these ions. It is shown that at the 2${\mathit{p}}^6$→2${\mathit{p}}^5$3d(4s) resonance a spectator structure appears in the ${\mathit{L}}_{23}$ ${\mathit{M}}_{23}$ ${\mathit{M}}_{23}$ Auger spectra, which shifts to higher kinetic energies with increasing photon energy. This structure originates from the 3${\mathit{p}}^{\mathrm{-}2}$3d(4s) final configuration arising as a product of the Auger resonant-inelastic-scattering process of the incident photons. We demonstrate that the peculiarities of this process and the role of the collapsing 3d electron in it can be largely understood in terms of an atomic treatment. The solid-state effects, caused by the crystal field and the lattice polarization, may play an additional role.