Olsson Emelie, Cornetta Lucas M, Ideböhn Veronica Daver, Wallner Måns, Parriani Marco, Squibb Richard J, Öhrwall Gunnar, Falcinelli Stefano, Karlsson Leif, Eland John H D, Ågren Hans, Feifel Raimund
Department of Physics, University of Gothenburg, Origovägen 6B, 412 58, Gothenburg, Sweden.
Instituto de Física da Universidade de São Paulo, R. do Matão, 1371, São Paulo, 05508-090, Brazil.
Sci Rep. 2025 May 6;15(1):15765. doi: 10.1038/s41598-025-01057-4.
We have measured the core-valence double ionization spectra of carbon suboxide above both the O 1s and C 1s edges. Following several core-valence cases known in the literature, to begin with the spectra are compared with the well-known single ionization valence photoelectron spectrum of this system, from which they surprisingly differ quite strongly. This motivates a comparison to electronic structure calculations carried out within the sudden approximation where the overlap between the core and valence orbital is included, while still assuming decoupling of the core and valence ionization events. The substantially improved agreement indicates that this more complex description is needed to model the core-valence double ionization process adequately in the present case. Accordingly, assignments of spectral features are made by comparison of our experimental and numerical spectra. Auger decay following C 1s hole formation at the chemically distinct central and outer C atoms shows strong selectivity in the final multiply charged states produced, for initial core-valence ionization, being consistent with the Auger decay from single core ionization. Comparison to calculations allows for the identification of the initial core ionization site for the Auger decay following core-valence ionization.
我们测量了一氧化三碳在O 1s和C 1s边以上的芯价双电离光谱。参照文献中已知的几个芯价情况，首先将这些光谱与该体系著名的单电离价光电子能谱进行比较，结果令人惊讶地发现它们差异很大。这促使我们将其与在突然近似下进行的电子结构计算进行比较，该计算考虑了芯轨道和价轨道之间的重叠，同时仍假设芯电离事件和价电离事件解耦。显著改善的一致性表明，在当前情况下，需要这种更复杂的描述来充分模拟芯价双电离过程。因此，通过比较我们的实验光谱和数值光谱来进行光谱特征的归属。在化学性质不同的中心C原子和外部C原子处形成C 1s空穴后的俄歇衰变，对于初始芯价电离，在产生的最终多重带电态中表现出很强的选择性，这与单核电离产生的俄歇衰变一致。与计算结果的比较有助于确定芯价电离后俄歇衰变的初始芯电离位点。
