Extended Absorption Fine Structure in the Soft X-Ray Region

Abstract

The K-absorption spectrum of Al and the L2,3-absorption spectra of Fe, Ni and Cu were measured. We evaluated the absorption coefficients of these metals in terms of the theory of EXAFS. Assuming that the absorbing atom is approximated by a screened Z+1 atom, the calculated results agree well with experiments.

Mapping Orbital-Resolved Magnetism in Single Lanthanide Atoms

“…Therefore, only 3s → 6p (M 1 ), 3p → 5d (M 2,3 ), and 3d → 4f (M 4,5 ) are the allowed electric dipole transitions that can be accessed using soft X-rays, with the double subscript index labeling the spin–orbit split core states (see Figure b). Due to the lower cross-section, the transitions involving Δl = −1 such as 3p → 6s and 3d → 6p are much less intense and generally not considered. , While M 4,5 edges of rare earths are routinely measured in many soft X-ray beamlines, the larger energy needed to access the core levels at the M 1 and M 2,3 edges requires a specific design of the X-ray optics . Here we measure the whole series of M transitions and thereby access the magnetic polarization of the individual electron shells contributing to the overall magnetization of the adatoms, especially of the outer shells contributing to electronic transport.…”

High-temperature self-energy corrections to x-ray absorption spectra

“…The solid curves denote the absorption with ground state atomic background while the dots represent the absorption with ΣGW (T > 0) selfenergy atomic background. The experimental measurement at ambient condition is shown as black cross [55].…”