Nanomaterials (Jun 2020)

Using the Emission of Muonic X-rays as a Spectroscopic Tool for the Investigation of the Local Chemistry of Elements

  • Matteo Aramini,
  • Chiara Milanese,
  • Adrian D. Hillier,
  • Alessandro Girella,
  • Christian Horstmann,
  • Thomas Klassen,
  • Katsuo Ishida,
  • Martin Dornheim,
  • Claudio Pistidda

DOI
https://doi.org/10.3390/nano10071260
Journal volume & issue
Vol. 10, no. 7
p. 1260

Abstract

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There are several techniques providing quantitative elemental analysis, but very few capable of identifying both the concentration and chemical state of elements. This study presents a systematic investigation of the properties of the X-rays emitted after the atomic capture of negatively charged muons. The probability rates of the muonic transitions possess sensitivity to the electronic structure of materials, thus making the muonic X-ray Emission Spectroscopy complementary to the X-ray Absorption and Emission techniques for the study of the chemistry of elements, and able of unparalleled analysis in case of elements bearing low atomic numbers. This qualitative method is applied to the characterization of light elements-based, energy-relevant materials involved in the reaction of hydrogen desorption from the reactive hydride composite Ca(BH4)2-Mg2NiH4. The origin of the influence of the band-structure on the muonic atom is discussed and the observed effects are attributed to the contribution of the electronic structure to the screening and to the momentum distribution in the muon cascade.

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