Dissolution, diffusion and permeation behavior of hydrogen in vanadium: a first-principles investigation
Jian Luo1, Hong-Bo Zhou, Yue-Lin Liu
1Department of Physics, Beihang University, Beijing, People's Republic of China.
Summary
This study investigates hydrogen behavior in vanadium, finding it prefers interstitial sites. Hydrogen diffuses rapidly in vanadium with a low energy barrier, crucial for material applications.
Area of Science:
- Materials Science
- Computational Physics
- Hydrogen Embrittlement Research
Background:
- Vanadium (V) is a body-centered cubic (bcc) metal with potential applications in hydrogen storage and fusion reactors.
- Understanding hydrogen (H) and its isotopes' behavior in metals is critical for predicting material performance and preventing failure.
- First-principles calculations offer a powerful tool for investigating atomic interactions and material properties at the quantum level.
Purpose of the Study:
- To investigate the stability and diffusion mechanisms of hydrogen in bcc vanadium using first-principles calculations.
- To determine the preferred interstitial sites for hydrogen atoms within the vanadium lattice.
- To quantify the diffusion barrier, diffusion coefficients, and permeation properties of hydrogen isotopes in vanadium.
Main Methods:
- Employed first-principles calculations to study hydrogen-vanadium interactions.
- Analyzed charge density distribution, Density of States (DOS), and Bader charge to understand hydrogen stability.
- Calculated diffusion barriers and utilized empirical theory to estimate diffusion coefficients and permeabilities.
Main Results:
- Identified the tetrahedral interstitial site (TIS) as the most stable site for a single hydrogen atom in bcc vanadium.
- Observed strong interactions between hydrogen and neighboring vanadium atoms, evidenced by charge density and electronic structure analysis.
- Determined a low diffusion barrier of 0.07 eV for hydrogen between neighboring TISs, indicating high mobility.
Conclusions:
- Hydrogen exhibits significant stability in bcc vanadium, primarily due to strong H-V interactions and the occupation of specific electronic states.
- The calculated diffusion coefficient (2.48 × 10⁻⁴ cm²/s) and permeability (2.19 × 10⁻⁹ mol m⁻¹ s⁻¹ Pa⁻¹/²) at 800 K suggest efficient hydrogen transport in vanadium.
- These findings are crucial for assessing vanadium's suitability in hydrogen-related technologies and understanding hydrogen embrittlement phenomena.
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