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. In this study, we demonstrate that analysing the kinetics of the absorption process with a combination of direct and indirect methods provides a much clearer and more detailed picture of the individual processes involved than the usual investigations in thermodynamic equilibrium do. To this end, we studied the well‐known Nb‐H system in an in‐situ experiment that combines several scattering methods simultaneously. 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. By comparing these quantities, 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.
Guasco et al. (Sun,) studied this question.