Journal of Synchrotron Radiation (Sep 2023)

The AXEAP2 program for Kβ X-ray emission spectra analysis using artificial intelligence

  • In-Hui Hwang,
  • Shelly D. Kelly,
  • Maria K. Y. Chan,
  • Eli Stavitski,
  • Steve M. Heald,
  • Sang-Wook Han,
  • Nicholas Schwarz,
  • Cheng-Jun Sun

DOI
https://doi.org/10.1107/S1600577523005684
Journal volume & issue
Vol. 30, no. 5
pp. 923 – 933

Abstract

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The processing and analysis of synchrotron data can be a complex task, requiring specialized expertise and knowledge. Our previous work addressed the challenge of X-ray emission spectrum (XES) data processing by developing a standalone application using unsupervised machine learning. However, the task of analyzing the processed spectra remains another challenge. Although the non-resonant Kβ XES of 3d transition metals are known to provide electronic structure information such as oxidation and spin state, finding appropriate parameters to match experimental data is a time-consuming and labor-intensive process. Here, a new XES data analysis method based on the genetic algorithm is demonstrated, applying it to Mn, Co and Ni oxides. This approach is also implemented as a standalone application, Argonne X-ray Emission Analysis 2 (AXEAP2), which finds a set of parameters that result in a high-quality fit of the experimental spectrum with minimal intervention. AXEAP2 is able to find a set of parameters that reproduce the experimental spectrum, and provide insights into the 3d electron spin state, 3d–3p electron exchange force and Kβ emission core-hole lifetime.

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