Photoion spectroscopy on isolated Mn atoms in the 2p → 3d excitation region. II. Decay processes of the excited states

Abstract

A series of time-of-flight (TOF) spectra of isolated Mn atoms were measured in the vicinity of 2p → 3d excitation states (635 to 656 eV) at a high-energy resolution. Synchrotron radiation was used as a light source. From this spectral data, charge-separated photoion-yield spectra and charge-state distribution as functions of the photon energy were obtained. The photoions resulting from the 2p → 3d excitation states are distributed from Mn+ to Mn6+, with the largest component being Mn3+ ions. Based on these spectra, the relaxation processes of the 2p → 3d excitation states are semi-quantitatively considered. For this purpose, highly excited states above the next ionization limit were calculated using the GRASP92 atomic code. It is found that single and double Auger shake-off processes play a central role in the formation of Mn5+ and Mn6+ ions. From the behavior of the charge-state distribution, the lowest 2p ionization limit has been determined to be 647.0 ± 0.3 eV.