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Mixed oxidation state of uranium in geological samples: HERFD-XAS and HERFD-XRF mapping at U M4 edge

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اقرأ أكثر حفظ في قائمتي
  • المؤلفون: (0000-0002-5445-2438) Bazarkina, E.; (0000-0003-4447-4542) Kvashnina, K.
  • المصدر:
    R3C 3eme Rencontres Rayonnement Radiochimie, 18.-20.06.2024, Nimes, France
  • نوع التسجيلة:
    Electronic Resource
  • الدخول الالكتروني :
    https://www.hzdr.de/publications/Publ-39224-1
    info:eu-repo/semantics/altIdentifier/purl/https://www.hzdr.de/publications/Publ-39224-1
  • معلومة اضافية
    • Publisher Information:
      2024
    • نبذة مختصرة :
      The complex behavior of uranium in natural environments is mainly controlled by the oxidation and reduction processes. The HERFD-XAS and HERFD-XRF measurements at U M4 edge open new perspectives for fingerprinting the oxidation state of uranium in natural samples in which U is concentrated (form own minerals) or present as a trace (down to ppm level). For numerous scientific fields such as geochemistry, biochemistry, and environmental geochemistry the knowledge of the oxidation state of uranium (U) present at the ppm level is of high importance. High-Energy Resolution Fluorescence Detection (HERFD) spectroscopy at U M4 edge is the most powerful method for the quantification of mixed oxidation states of U [2]. The main edge of the U M4 HERFD-XAS spectrum arises from the electronic transitions from the U 3d3/2 to 5f level, i.e. highly sensitive to the oxidation state (Figure 1). Even if the local atomic coordination of U may impact the energy maximum (generally by 0.1 – 0.2 eV), the principal component analyses of HERFD-XAS spectra at U M4 edge is straightforward for accurate quantification of different oxidation states even if the pure structural end-members are not known. In addition, the HERFD X-ray fluorescence (XRF) mapping at U M4 edge allows 2D visualization of U(IV), U(V) and U(VI) distribution and their relations. Thus, the HERFD-XAS and HERFD-XRF are exceptional techniques for studies focused on the U state and behavior in natural environments.
    • الموضوع:
      info:eu-repo/semantics/publishedVersion; doc-type:lecture; Text
    • Availability:
      Open access content. Open access content
      Restricted Access
    • Note:
      English
    • Other Numbers:
      DERBS HZDR:PUBLDB:39224-1
      1456321392
    • Contributing Source:
      ROBIS REPOSITORY
      From OAIster®, provided by the OCLC Cooperative.
    • الرقم المعرف:
      edsoai.on1456321392
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