Berlin 2018 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 20: Topical session (Symposium MM): Hydrogen in Materials

MM 20.5: Vortrag

Dienstag, 13. März 2018, 12:00–12:15, H 0107

Mechanical stress upon hydrogen absorption in Nb-Fe Films — •Philipp Klose, Magnus Hamm, Vladimir Roddatis, and Astrid Pundt — Institut für Materialphysik, Friedrich-Hund-Platz 1, 37077 Göttingen, Deutschland

Hydrogen absorption in thin films adhered to rigid substrates results in compressive mechanical in-plane stresses.[1,2,3] These stresses can lead to changes in the material's properties. While the in-plane film stress increases linearly on the hydrogen content for low hydrogen concentrations, deviations from the linearity appear at the yield stress [3,4]. The yield stress inversely depends on the film thickness.[5] For hydrogen loaded Niobium films, linearity is maintained to 1 H/Nb, for films below 6 nm and mechanical stress of up to -10 GPa is achieved.[5]

The yield stress can also be affected by alloying.[6] In this presenation we study the stress-development upon hydrogen loading in niobium-iron films of differing compositions. Films of different thickness were prepared by argon-cathode beam sputtering. Electrochemical hydrogen loading was performed during in-plane stress and in-situ XRD-measurements. By alloying the yield stress is shifted to much higher values. This will be discussed with respect to the Hall-Petch relation and the lattice coherency.

This work is financially supported by the DFG via project PU131/12-1. [1] J. Weissmuller et al. , Phil. Mag. Lett. 80 (2000), [2] S. Wagner et al., Appl. Phys. Lett. 92 (2008), [3] U. Laudahn et al., JALCOM (1999), [4] A. Pundt et al., Phys. Rev. B 61.15 (2000), [5] Hamm, M., et al. APL 106 (2015), [6] P. Klose et al. IJHE (2017).