Applications of Zr–V hydrogen getters in vacuum-plasma devices: Phase-structural and hydrogen sorption characteristics

Lototsky, M.V.; Yartys, V.A.; Klochko, Yevgeniy; Borisko, V. N.; Starovoitov, R. I.; Azhazha, V.M.; V’yugov, P.N.

doi:10.1016/j.jallcom.2005.02.086

Cited by 19 publications

(7 citation statements)

References 7 publications

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“…Since the interpretability of our compositional ML model has recently elucidated a simple design rule, we can even perform a priori selection of candidates with a desired thermodynamic stability simply based on features derived solely from their proposed composition. This exercise reveals that the equilibrium pressure of the HEA hydrides in the data set spans many orders of magnitude and signifies usefulness in a variety of applications, from H 2 -getters to storage materials. Several of these novel HEA compositions were rationally selected (based on the ML model-based design rule), synthesized, and hydrogenated to demonstrate the large destabilization that can be induced through compositional modifications within the data set.…”

Section: Introductionmentioning

confidence: 98%

Data-Driven Discovery and Synthesis of High Entropy Alloy Hydrides with Targeted Thermodynamic Stability

Witman

Ling

et al. 2021

Chem. Mater.

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Solid-state hydrogen storage materials that are optimized for specific use cases could be a crucial facilitator of the hydrogen economy transition. Yet the discovery of novel hydriding materials has historically been a manual process driven by chemical intuition or experimental trial-and-error. Data-driven materials' discovery paradigms provide an alternative to traditional approaches, whereby machine/statistical learning (ML) models are used to efficiently screen materials for desired properties and significantly narrow the scope of expensive/time-consuming first-principles modeling and experimental validation. Here we specifically focus on a relatively new class of hydrogen storage materials, high entropy alloy (HEA) hydrides, whose vast combinatorial composition space and local structural disorder necessitates a data-driven approach that does not rely on exact crystal structures in order to make property predictions. Our ML model quickly screens hydride stability within a large HEA space and permits down selection for laboratory validation based not only on targeted thermodynamic properties, but also secondary criteria such as alloy phase stability and density.To experimentally verify our predictions, we performed targeted synthesis and characterization of several novel hydrides that demonstrate significant destabilization (70x increase in equilibrium pressure, 20 kJ/molH 2 decrease in desorption enthalpy) relative to the benchmark HEA hydride, TiVZrNbHfH x . Ultimately, by providing a large composition space in which hydride thermodynamics can be continuously tuned over a wide range, this work will enable efficient materials selection for various applications, especially in areas such as metal hydride based hydrogen compressors, actuators, and heat pumps. File list (3) download file view on ChemRxiv HEAH2.pdf (4.48 MiB) download file view on ChemRxiv HEAH2SI.pdf (2.79 MiB) download file view on ChemRxiv rHEA_allpredictions_final.csv (63.15 KiB)

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Section: Introductionmentioning

confidence: 98%

Data-Driven Discovery and Synthesis of High Entropy Alloy Hydrides with Targeted Thermodynamic Stability

Witman

Ling

et al. 2021

Chem. Mater.

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“…A distinctive feature of getter hydride-forming intermetallics is the low equilibrium pressure of hydrogen sorptiondesorption at the temperatures close to the room ones. This feature allows using them in various devices operating at sub-atmospheric pressures, in particular, to ensure the operation of various physical and technical devices, such as injectors of thermonuclear installations, ion sources of accelerators, gas power systems of vacuum-plasma installations, gas lasers and other devices using hydrogen as a working medium [ [14], Error! Reference source not found.…”

Section: Ensuring the Operation Of Various Physical And Technical Dev...mentioning

confidence: 99%

The Role of Surface in Hydride Formation Processes

Litvinov,

Okseniuk,

Shevchenko

et al. 2023

East Eur. J. Phys.

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Several LaNi5-based hydrogen storage alloys were studied using secondary ion mass spectrometry (SIMS) technique. Ar+ ions with the energy of 10 - 18 keV were used as primary ions. The study of the initial stages of the processes of LaNi5-based alloys interaction with hydrogen under the experimental conditions showed that on the areas of clean surface, hydrogen formed chemical compounds with the both of the main components of the alloy: nickel and lanthanum. As hydrogen accumulates on the surface and in the near-surface region, a hydrogen-containing structure is formed, which is characterized by a certain stoichiometric ratio of components. Nickel in this structure has strong chemical bonds with two hydrogen atoms, and lanthanum – with two or more hydrogen atoms. Along with such compounds, some structures with lower hydrogen content are also formed. The formed hydrogen-containing structure includes both main alloy components, La and Ni for all the studied samples, even though only lanthanum is generally accepted to be the hydride-forming element in such alloys. The SIMS studies of the chemical composition of the surface monolayers of the intermetallic alloy LaNi5, in the process of its interaction with oxygen, showed the following. As a result of the oxygen interaction with the alloy, a complex chemical structure including oxygen, lanthanum and nickel is formed on the surface and in the near-surface region of LaNi5. Oxygen in such a structure, similarly to hydrogen, forms strong chemical bonds with both components of the alloy. This is indicated by the presence in the mass spectra of a large set of oxygen-containing emissions of positive and negative secondary ions with lanthanum and nickel, as well as oxygen-containing lanthanum-nickel cluster secondary ions. The formed oxide compounds have a three-dimensional structure and occupy tens of monolayers. Oxygen poisoning of the surface of the hydride-forming alloy LaNi5 can occur regardless of whether the surface of the alloy was clean from the very beginning or it was covered with a layer of hydrogen-containing chemical compounds.

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“…Annealing at 500 °C recrystallizes the amorphous phase into cubic Zr2Fe, or more probably its oxidized form -Zr4Fe2Ox, as this phase is known to be stabilized by small amount of oxygen [54]. It is worth noting that formation of stable oxygen-containing intermetallic -phases is a feature of not only Zr-Fe-(O) system but also many other systems comprising Zr (and/or Ti) together with other transition metals (e.g., V) and non-metal Z = O, B, N; to form, for example, Zr3V3Zx [55][56][57].The as-spun ribbons show very slow absorption rate at RT (full hydrogenation in 6 h) whereas annealed ribbons absorb readily hydrogen in 30 s though a reduced capacity by 33%, attributed to an absorption-disproportionation reaction. Nevertheless, such ribbons exhibit very good sorption properties, even in oxidized atmosphere.…”

Section: Zr-fementioning

confidence: 99%