Behaviors of helium in vanadium: Stability, diffusion, vacancy trapping and ideal tensile strength

Gui, Li-Jiang; Liu, Yuelin; Wang, Weitian; Liu, Yinan; Arshad, Kameel; Zhang, Ying; Lü, Guang-Hong; Yao, Jing

doi:10.1016/j.pnsc.2013.08.002

Cited by 15 publications

(7 citation statements)

References 32 publications

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“…It is also interesting to note that the energy barriers for He diffusion in Ti 3 AlC 2 , both along the c-axis and in the ab plane, are much larger than those in metals, [29][30][31] indicating that the rate of bubble growth in Ti 3 AlC 2 is slower than that of metals. Hence, Ti 3 AlC 2 possesses a higher stability against He irradiation than metals.…”

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confidence: 99%

New insight into the helium-induced damage in MAX phase Ti3AlC2 by first-principles studies

Bai

Zha

et al. 2015

The Journal of Chemical Physics

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In the present work, the behavior of He in the MAX phase Ti 3 AlC 2 material is investigated using first-principle methods. It is found that, according to the predicted formation energies, a single He atom favors residing near the Al plane in Ti 3 AlC 2 . The results also show that Al vacancies are better able to trap He atoms than either Ti or C vacancies. The formation energies for the secondary vacancy defects near an Al vacancy or a C vacancy are strongly influenced by He impurity content. According to the present results, the existence of trapped He atoms in primary Al vacancy can promote secondary vacancy formation and the He bubble trapped by Al vacancies has a higher tendency to grow in the Al plane of Ti 3 AlC 2 . The diffusion of He in Ti 3 AlC 2 is also investigated. The energy barriers are approximately 2.980 eV and 0.294 eV along the c-axis and in the ab plane, respectively, which means that He atoms exhibit faster migration parallel to the Al plane. Hence, the formation of platelet-like bubbles nucleated from the Al vacancies is favored both energetically and kinetically. Our calculations also show that the conventional spherical bubbles may be originated from He atoms trapped by C vacancies. Taken together, these results are able to explain the observed formation of bubbles in various shapes in recent experiments. This study is expected to provide new insight into the behaviors of MAX phases under irradiation from electronic structure level in order to improve the design of MAX phase based materials. C 2015 AIP Publishing LLC. [http://dx

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confidence: 99%

New insight into the helium-induced damage in MAX phase Ti3AlC2 by first-principles studies

Bai

Zha

et al. 2015

The Journal of Chemical Physics

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“…Helium was expected to have a similar effect as argon. Theoretically, helium can pass through vanadium, but low solubility makes the passage highly unlikely . Since the solubility of helium is low, competitive sorption as with nitrogen might be negligible.…”

Section: Resultsmentioning

confidence: 99%

“…Theoretically, helium can pass through vanadium, but low solubility makes the passage highly unlikely. 19 Since the solubility of helium is low, competitive sorption as with nitrogen might be negligible. Thus, helium only fostered the diluted partial pressure of hydrogen during the thermal treatment.…”

Section: Resultsmentioning

confidence: 99%

Influence of Gas for Thermal Treatment on Hydrogen Permeation in V–Ni Alloy Membranes

2023

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Hydrogen separation is an important step for the utilization of hydrogen energy. Metallic alloys, such as vanadium−nickel, are potential hydrogen separation materials. Due to the strong propensity of vanadium to form oxides and hydrides, vanadium alloy has a lower hydrogen permeability, and it is difficult to maintain the permeability over time. Therefore, special preparation processes such as Pd coating have been suggested for hydrogen separation vanadium-based membranes. However, aside from the prohibitive price of palladium, the interdiffusion of palladium and vanadium makes the coated membrane inviable to be used at a high temperature. Thermal treatment with inert gas was investigated in this study to assess the applicability of the vanadium alloy without palladium coating for hydrogen separation and clarify the mechanism behind the thermal treatment. Argon is inert with vanadium and displayed permeability recovery after 43 h thermal treatment, but the permeability declined under certain conditions. In contrast, nitrogen is known to interact with vanadium and the hydrogen permeability was maintained at a level lower than the test with argon. Given that nitrogen can compete with hydrogen for the active sites on vanadium, nitrogen might hinder hydrogen adsorption and hydride formation, whereas argon reduced the partial pressure of hydrogen during the thermal treatment, enhancing the driving force of hydrogen desorption. In the X-ray diffraction spectrum, vanadium hydrides and oxides were confirmed after hydrogen permeation and thermal treatment. In the X-ray photoelectron spectroscopy data, oxygen was a dominant element due to vanadium oxides and adsorbed nitrogen was also observed. According to binding energy shifts of nitrogen, nitrogen used for thermal treatment might substitute or compete for active sites with adsorbed nitrogen and hydrogen, existing in vanadium lattice. Although thermal treatment can be used to recover hydrogen permeability, the alloy cannot be recovered as hydrogen-free. However, results demonstrate the potential of thermal treatment to complement an uncoated vanadium alloy for a hydrogen separation membrane.

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“…Recently, numerous investigations have been made on the effects of helium (He)-induced defects and impurities in metals and intermetallics since this is an important issue for metals considered as structural materials in reactors [1][2][3]. V and its alloys are regarded among the most promising candidates for structural materials because of their excellent mechanical properties, high thermal conductivity, good resistance to irradiation-induced swelling and damage, and low activation properties [4,5].…”

Section: Introductionmentioning

confidence: 99%

“…Even at relatively low concentrations, He may potentially cause material embrittlement [6]; at higher concentrations, He can lead to the formation of He bubbles [6][7][8][9] and void swelling [10,11]. Consequently, the influence of He content in V is an important issue and requires more investigations [3]. Voxygen systems are also very interesting and, in a certain sense, unique [12].…”

Section: Introductionmentioning

confidence: 99%

Tuning surface porosity on vanadium surface by low energy He+ ion irradiation

Tripathi

Novakowski

Hassanein

2016

Applied Surface Science

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In the present study, we report on tuning the surface porosity on vanadium surfaces using highflux, low-energy He + ion irradiation as function of sample temperature. Polished, mirror-finished vanadium samples were irradiated with 100 eV He + ions at a constant ion-flux of 7.2  10 20 ions m-2 s-1 for 1 hour duration at constant sample temperatures in the wide range of 823-1173 K. Our results show that the surface porosity of V 2 O 5 (naturally oxidized vanadium porous structure, after taking out from UHV) is strongly correlated to the sample temperature and is highly tunable. In fact, the surface porosity significantly increases with reducing sample temperature and reaches up to ~87%. Optical reflectivity on these highly porous V 2 O 5 surfaces show ~0% optical reflectivity at 670 nm wavelength, which is very similar to that of "black metal". Combined with the naturally high melting point of V 2 O 5 , this very low optical reflectivity suggests potential application in solar power concentration technology. Additionally, this topdown approach guarantees relatively good contact between the different crystallites and avoids electrical conductivity limitations (if required). Since V 2 O 5 is naturally a potential photocatalytic material, the resulting sub-micron-sized cube-shaped porous structures could be used in solar water splitting for hydrogen production in energy applications.

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Behaviors of helium in vanadium: Stability, diffusion, vacancy trapping and ideal tensile strength

Cited by 15 publications

References 32 publications

New insight into the helium-induced damage in MAX phase Ti3AlC2 by first-principles studies

New insight into the helium-induced damage in MAX phase Ti3AlC2 by first-principles studies

Influence of Gas for Thermal Treatment on Hydrogen Permeation in V–Ni Alloy Membranes

Tuning surface porosity on vanadium surface by low energy He+ ion irradiation

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