X-ray Emission Spectroscopy (XES)

X-ray emission spectroscopy (XES) measures the energy dependence of the emitted X-ray from the decay of the excited state caused by X-ray absorption.

The energy of the incident beam is set to a few hundred eV above the absorption edge for nonresonant X-ray emission spectroscopy, or the energy can be scanned through the absorption edge for full resonant X-ray emission spectroscopy.

XES spectra are most sensitive for transition metals such as Mn, Fe, Co, Ni, and Cu where there is a strong overlap between the electronic configuration of the S and P electrons.
 

The multilayer monochromator at 25-ID will allow sub-second integration time for mapping. The graphic at right shows how KB mirrors can be used to focus photons onto the sample, while a miniature Von Hamos spectrometer directs flourescence to an area detector (1).

The Spectroscopy group also boasts a multi element spectrometer with large working distances for in-situ measurements, capable of collecting non-resonant spectra from multiple elements simultaneously. It is ideal for battery materials with a variety of transition metals (2).

(1) Von Hamos spectrometer design

(2) Next generation multi-element spectrometer

Sun, C.-J.; Solovyev, M. A.; Heald, S. et.al. Advanced X-Ray Emission Spectrometers.

US Patent 2023/0288352 A1, 2023.

Data Collection Examples

Below are two examples of XES data. On the left is a Co emissions spectra from a catalyst using mini-XS (3). The second shows the data distinguishing Ni and NiCl2 in a battery electrode (4).

(3) Co emissions from a catalyst using mini-XS

The Kβ_1,3 peak shifts for Co with oxygen conpared to sulfur ligands

(4) Ni and NiCl2 in a battery electrode.

Bowden et al, J. Power Sources 247, 517-526 (2014)