Application of an atomic relaxation model for the interpretation of O1s to Rydberg excited Auger electron spectra of molecular oxygen

Core-level spectroscopy and dynamics of free molecules

“…Applying the spectator-electron shake relaxation model from Refs. [53,54], and using, to a large extent, the assignments for the core-excited resonances as available from the literature, many of the observed spectator Auger-electron final states could be assigned in terms of cationic Rydberg series. Vice versa, the resonant Auger-electron spectra were used for consistency tests of the literature assignments for the core-excited intermediate Rydberg states.…”

“…Ref. [53] for the corresponding absorption curve), were compared to the normal Auger spectrum of O 2 recorded well above the O1s ionisation thresholds at the photon energy of 650 eV. Interestingly, the resonantly excited electron spectra revealed in the inner valence region above 35 eV binding energy, which is governed by spectator decay, quite some reminiscence to the ordinary Auger electron spectrum as exemplary shown in Fig.…”

“…[53,55] indicate, the O1s near-edge X-ray absorption region of O 2 is quite complex. In order to obtain a deeper insight, Feifel et al [56] investigated the valence character of this resonance region by means of participator Auger decay spectroscopy, performed at selected photon energies, and by means of partial ion yield x-ray absorption spectroscopy.…”

“…Sorensen and coworkers [53] performed recently a study where O1s → Rydberg excited resonant Auger spectra of O 2 , recorded at the photon energies 541.80 and 541.97 eV (see e.g. Ref.…”

“…The assignments of the resonant spectra assume that the relevant intermediate neutral states at 541.80 and 541.97 eV governing the Auger decay are essentially the ν = 0 and 1 vibrational components of the (O1s) −1 ( 4 Σ − u ) 4pσ Rydberg state, and reasons for this assumption are given in Ref. [53].…”