Discovery of an energy-dependent many-body process in the K β spectrum of manganese metal using extended-range high-energy-resolution fluorescence detection with advanced structural insights from principal component analysis

DOI: 10.1107/S2052252525005573

Authors: Jack Stephens (University of Melbourne) , Ramesh Rijal (University of Melbourne) , Daniel Sier (University of Melbourne) , Nicholas T. T. Tran (University of Melbourne) , Jonathan W. Dean (University of Melbourne) , Paul Di Pasquale (La Trobe University) , Tony Kirk (La Trobe University) , Minh Dao (La Trobe University) , Chanh Q. Tran (La Trobe University) , Shusaku Hayama (Diamond Light Source) , Sofia Diaz-Moreno (Diamond Light Source) , Christopher T. Chantler (University of Melbourne)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Iucrj , VOL 12

State: Published (Approved)
Published: September 2025
Diamond Proposal Number(s): 39257

Abstract: The discovery of the novel n = 2 satellite transition in the Kβ emission spectrum of manganese and its evolution with incident photon energy are presented. Using the XR-HERFD (extended-range high-energy-resolution fluorescence detection) technique, we conclusively demonstrate the existence of this phenomenon with a statistical significance corresponding to 652 σse across the measured spectrum, far above the discovery threshold of 3–6 σse. We apply principal component analysis (PCA) to the XR-HERFD data to extract advanced structural insights. The evolution of this novel spectral feature and physical process are quantified by incorporating regression, revealing the increase in intensity over a wide range of incident photon energies. We validate these findings through independent test data. These results directly challenge the conventional treatment of the many-body reduction factor S02 as a constant independent of incident photon energy in the standard XAFS (X-ray absorption fine structure) equation. Thereby, these results present compelling evidence that S02 should be modelled as a varying function of incident photon energy, marking the first observation of this behaviour in Kβ spectra. This facilitates a greater quantitative understanding of HERFD spectra and a comprehensive representation of many-body effects in condensed matter systems.

Journal Keywords: extended-range high-energy-resolution fluorescence detection; materials science; inelastic X-ray scattering; X-ray absorption fine structure; manganese; Kβ spectra; shake processes; principal component analysis; satellites; many-body reduction factor; man

Subject Areas: Physics, Materials


Instruments: I20-Scanning-X-ray spectroscopy (XAS/XES)

Added On: 24/08/2025 10:33

Discipline Tags:

Physics Hard condensed matter - structures Materials Science

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) High Energy Resolution Fluorescence Detected XAS (HERFD-XAS)