Conference Presentation (After Call)

FZJ-2026-04440

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Kinetic study of hydrogen absorption in thin films by measurement of resonant neutron reflectometry, resistance, X-ray diffraction and reflection

Pütter, S. (Corresponding author)FZJ* ; Guasco, L. ; Keller, T. ; Keimer, B. ; Silvi, L. ; Paulin, M. A.

2026

Abstract: Absorption of hydrogen in thin films is important for a wide range of applications, including hydrogen membranes, sensor technology, and programmable resistors for artificial neural networks. Resonant neutron reflectometry has proven to be a very useful tool for investigation of hydrogen uptake.[1] The hydrogen concentration within a thin film can be studied as function of time. Only recently, we have demonstrated that analysing the kinetics of the absorption process with a combination of direct and indirect methods provides an even clearer and more detailed picture of the individual processes involved than the usual investigations in thermodynamic equilibrium do.[2]Our test system is the well-known Nb-H system. Neutron reflectometry directly measures the hydrogen concentration in the layer. X-ray reflectometry and diffraction determine layer thicknesses and atomic lattice spacing. Electrical resistance, an easily measurable yet indirect quantity, reveals general trends.We performed simultaneous in-situ measurements of combinations of these methods. As a consequence the measured quantities can be compared directly. For hydrogen absorption in Nb thin films we observed four regimes of the absorption process over time. These phases include different absorption mechanisms, as well as swelling and defect formation. The method used has a time resolution of a few seconds, is non-destructive, and is therefore also suitable for in-operando studies.[1] L. Guasco et al., Nature Communications 13, 131486 (2022) https://doi.org/10.1038/s41467-022-29092-z[2] L. Guasco et al. Advanced Functional Materials vol. n/a, p. e75202 (2026) https://doi.org/10.1002/adfm.75202

Keyword(s): Energy (1st) ; Materials Science (2nd)

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Contributing Institute(s):

1. JCNS-4 (JCNS-4)
2. JCNS-FRM-II (JCNS-FRM-II)
3. Heinz Maier-Leibnitz Zentrum (MLZ)

Research Program(s):

1. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)
2. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)

Experiment(s):

1. MBE-MLZ: Molecular Beam Epitaxy at MLZ

Appears in the scientific report 2026

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