Resonant Auger electron spectroscopic study at the symmetry-forbidden excitation below the S -shell threshold of SF is reported. Partial electron yield and resonant Auger spectra have been measured by using monochromatized undulator synchrotron radiation. By changing the photon energy in small steps, a so-called 2D map is produced. In this map, the dipole-forbidden transition exhibits spectral features (e.g., an S-shaped dispersion relation), which are well known and understood for dipole-allowed transitions. We validate by a theory that for the case of dipole-forbidden transitions, these spectral features can be analyzed in the same way as previously established for the dipole-allowed ones. This approach grants information on the nuclear dynamics in the -shell core-excited states of SF on the femtosecond (fs) timescale. In particular, for the potential-energy curves of the states S and S , the slopes at the equilibrium distance of the ground state are derived. Symmetry breaking as a result of ultrafast vibronic coupling is revealed by the population of the electronically forbidden excited state.
Resonant Auger decay induced by the symmetry-forbidden 1a1g → 6a1g transition of the SF6 molecule
Present address: Nano and Molecular Systems Research Unit, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland.
Present address: Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607 Hamburg, Germany and Department of Physics, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg, Germany.
Note: This manuscript is a part of the Special Topic Collection Commemorating the Career of David Arthur Shirley.
A. C. F. Santos, O. Travnikova, N. Boudjemia, T. Marchenko, R. Guillemin, I. Ismail, D. Koulentianos, D. Céolin, F. Gel’mukhanov, M. Simon, M. N. Piancastelli, R. Püttner; Resonant Auger decay induced by the symmetry-forbidden 1a1g → 6a1g transition of the SF6 molecule. J. Vac. Sci. Technol. A 1 July 2022; 40 (4): 042801. https://doi.org/10.1116/6.0001890
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