Resonant double core-hole spectroscopy of ultrafast decay dynamics in Fe complexes

Abstract

Resonant double core-hole (DCH) spectroscopy allows observation of ultrafast dynamic processes in small 3d-metal compounds in the gas phase. Using the intense X-Ray pulses of the European XFEL, electron and ion spectroscopy was used to reveal the signature of iron 2p2 resonant DCH excitation in iron pentacarbonyl and ferrocene. Comparing the experimental results to theoretical calculations reconstructs single core-hole (SCH) and DCH photon-matter interactions in the two targets. The DCH Auger-Meitner electron signals offer insight into the electron dynamics during the core-hole lifetime and their dependence on the chemical environment. The product ions show evidence for DCH processes in multiply charged iron cations.