Author: Bornmann, B.
Paper Title Page
MOPAB401 In-Situ EXAFS Investigations of Nb-Treatments in N2, O2 and N2-O2 Mixtures at Elevated Temperatures 1214
 
  • P. Rothweiler, B. Bornmann, J. Klaes, D. Lützenkirchen-Hecht, R. Wagner
    University of Wuppertal, Wuppertal, Germany
 
  Funding: We gratefully acknowledge financial support by the German Federal Ministry of Education and Research (BMBF) under project No. 05H18PXRB1.
Smooth polycrystalline Nb metal foils were treated in dilute gas atmospheres using a temperature of 900 °C. Transmission mode X-ray absorption spectroscopy (EX-AFS) at the Nb K-edge was used to investigate changes in the atomic short-range order structure of the bulk Nb-material in-situ. The experiments were performed in a dedicated high-vacuum cell that allows treatments in a dilute gas atmosphere and temperatures of up to 1200 °C. Typical treatments include (i) pre-heating at 900 °C under high-vacuum, (ii) gas exposure at the desired pressure and temperature, and (iii) cooldown to room temperature under vacuum. EXAFS data were collected during the entire procedure with a time resolution of 1 s. For the treatments in N2 at T = 900°C, the data show subtle changes in the Nb-EXAFS, that are compatible with N-doping of the bulk Nb, and the results suggest Nb uptake on octahedral interstitial sites. However, even a small O2-partial pressure leads to distinct oxidation of the Nb. The results will be discussed in more detail in the presentation.
 
poster icon Poster MOPAB401 [2.032 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB401  
About • paper received ※ 19 May 2021       paper accepted ※ 26 May 2021       issue date ※ 27 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)