Si 1s(-1), 2s(-1) and 2p(-1) lifetime broadening of SiX4 (X = F, Cl, Br, CH3) molecules SiF4 anomalous behaviour reassessed

• Published in: Physical chemistry chemical physics : PCCP Vol. 21; no. 17; p. 8827
• Main Authors: Puettner, Ralph, Marchenko, Tatiana, Guillemin, Renaud, Journel, Loic, Goldsztejn, Gildas, Ceolin, Denis, Takahashi, Osamu, Ueda, Kiyoshi, Lago, Alexsandre F., Piancastelli, Maria Novella, Simon, Marc
• Format: Journal Article
• Language: English
• Published: 2019
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c8cp07369d

The Si 1s(-1), Si 2s(-1), and Si 2p(-1) photoelectron spectra of the SiX4 molecules with X = F, Cl, Br, CH3 were measured. From these spectra the Si 1s(-1) and Si 2s(-1) lifetime broadenings were determined, revealing a significantly larger value for the Si 2s(-1) core hole of SiF4 than for the same core hole of the other molecules of the sequence. This finding is in line with the results of the Si 2p(-1) core holes of a number of SiX4 molecules, with an exceptionally large broadening for SiF4. For the Si 2s(-1) core hole of SiF4 the difference to the other SiX4 molecules can be explained in terms of Interatomic Coulomb Decay (ICD)-like processes. For the Si 2p(-1) core hole of SiF4 the estimated values for the sum of the Intraatomic Auger Electron Decay (IAED) and ICD-like processes are too small to explain the observed linewidth. However, the results of the given discussion render for SiF4 significant contributions from Electron Transfer Mediated Decay (ETMD)-like processes at least plausible. On the grounds of our results, some more molecular systems in which similar processes can be observed are identified.