Sarac, BaranZadorozhnyy, VladislavIvanov, Yurii P.Kvaratskheliya, AskarKetov, SergeyKarazehir, TolgaGumrukcu, Selin2025-01-062025-01-0620200378-77531873-275510.1016/j.jpowsour.2020.2287002-s2.0-85089383669https://doi.org/10.1016/j.jpowsour.2020.228700https://hdl.handle.net/20.500.14669/2717The hydrogenation and oxide formation behavior of Fe-Ni-based metallic glasses (MGs), where measurements by the conventional gas-solid reaction method are difficult, is analyzed by a two-step approach: chronoamperometry followed by cyclic voltammetry (CA + CV). We introduce a concept of effective volume by measuring the thickness of the region where the hydrogen and hydroxyl ion interactions with Fe-based MG take place, which is characterized by high-angle annular dark-field scanning transmission electron microscopy. A very constant film thickness influenced by the OH- and H+ is confirmed by TEM, where the chemical homogeneity is maintained within this region. The weight percent of hydrogen and the corresponding hydrogen-to-metal ratio are determined as 1.16% and 0.56, respectively. When compared to previous studies conducted by the electrochemical- permeation method, the H/M ratio is found to be an order of magnitude larger. Electrochemical impedance spectroscopy (EIS) and subsequent equivalent circuit modeling (ECM) of the tested ribbons resolve the surface-diffusion processes for hydride formation and oxidation kinetics. This contribution provides a different perspective for the design and study of low-cost and high-performance amorphous nanofilms for hydrogenenergy applications, particularly when the common gas-adsorption methods are problematic.eninfo:eu-repo/semantics/closedAccessMetallic glassHydrogen-to-metal ratioElectrosorptionGas-solid reactionsHigh-angle annular dark-field scanning transmission electron microscopyElectrochemical impedance spectroscopyArticleQ1475WOS:000573640600001Q1