Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DS: Fachverband Dünne Schichten
DS 12: Gaede-Jubiläumssitzung
DS 12.4: Hauptvortrag
Donnerstag, 20. März 2025, 18:00–18:30, H3
Ultrafast X-ray photoelectron spectroscopy and photoelectron diffraction — •Philip Hofmann — Department of Physics and Astronomy, Aarhus University, Denmark
X-ray photoelectron spectroscopy (XPS) is an experimental tool capable of accurately determining the core level binding energies of atoms. This energy is not only element-specific but also provides detailed information on the atoms’ oxidation state and chemical environment, making XPS an essential tool for studying catalytic processes. XPS line shapes have also attracted considerable interest, leading to the development of many-body theories to study the solid’s electronic and vibrational properties. Finally, the core level photoemission intensity can be interpreted as a diffraction pattern that gives access to the emitting atom’s local geometrical environment in an experimental approach called X-ray photoelectron diffraction (XPD).
The increasing availability of ultrafast X-ray sources at free electron lasers now opens the opportunity to take XPS and XPD into the ultrafast time domain and this talks will give two recent examples. For graphene, it is shown that a study of the time-dependent XPS line shape can reveal detailed insight into the excitation of the system, directly giving access to parameters such as the electronic temperature. A demonstration of XPD is given in which the motion of surface atoms of the topological insulator Bi2Se3 is tracked after the excitation of a coherent optical phonon.