| アイテムタイプ |
itemtype_ver1(1) |
| 公開日 |
2026-03-02 |
| タイトル |
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タイトル |
Ab initio path-integral simulations of hydrogen-isotope diffusion in face-centred cubic metals |
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言語 |
en |
| 著者 |
Kimizuka, Hajime
Ogata, Shigenobu
Thomsen, Bo
Shiga, Motoyuki
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| アクセス権 |
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アクセス権 |
embargoed access |
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アクセス権URI |
http://purl.org/coar/access_right/c_f1cf |
| 権利 |
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権利情報 |
This is the Accepted Manuscript version of an article accepted for publication in [Journal of Physics: Condensed Matter]. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at [https://doi.org/10.1088/1361-648X/adc060] |
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言語 |
en |
| 権利 |
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権利情報 |
“This Accepted Manuscript is available for reuse under a CC BY-NC-ND licence after the 12 month embargo period provided that all the terms of the licence are adhered to” |
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言語 |
en |
| 内容記述 |
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内容記述タイプ |
Abstract |
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内容記述 |
Lighter isotopes typically diffuse faster than heavier isotopes; however, the case is not necessarily true for H. Predicting the kinetics of H isotope transport and reactions in substances remains a fundamental challenge in material and condensed matter physics. The peculiar experimentally observed isotope effect on H diffusivities in face-centred cubic (fcc) metals has long been an unresolved problem. Using an ab initio path-integral approach to explore the quantum mechanical nature of both electrons and nuclei, this study successfully predicts H isotope diffusivities in fcc Pd over a wide temperature range. The temperature dependence of the diffusivities follows an unusual ‘reversed-S’ shape on Arrhenius plots. This irregular behaviour, arising from the competition between different nuclear quantum effects (NQEs) with different temperature dependencies, reveals the mechanism of anomalous crossovers between normal and reversed isotope effects. The results illustrate that this phenomenon is common in other fcc metals (e.g. Cu and Ag), where H atoms prefer to occupy octahedral (O) sites. Conversely, in Al, where H atoms prefer to occupy tetrahedral (T) sites, the dependence of H diffusivities on temperature exhibits a familiar ‘C’ shape. A lattice expansion of approximately 1%–2% causes the stable position of H atoms dissolved in Pd to shift from the O to T sites, and H diffusion in expanded Pd is no longer suppressed by NQEs, as observed in Al. This finding has important implications for interpreting kinetic processes involving the crossover from classical to quantum behaviour of H atoms moving between different interstitial sites. Path-integral simulation results describing the approximate quantum dynamics of the Pd–H system, using a machine-learning-based interatomic potential with accuracy similar to the density functional theory calculations, are presented. This computational approach paves the way for elucidating the quantum behaviour of H isotopes in various materials. |
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言語 |
en |
| 出版者 |
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出版者 |
IOP publishing |
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言語 |
en |
| 言語 |
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言語 |
eng |
| 資源タイプ |
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資源タイプresource |
http://purl.org/coar/resource_type/c_6501 |
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タイプ |
journal article |
| 出版タイプ |
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出版タイプ |
AM |
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出版タイプResource |
http://purl.org/coar/version/c_ab4af688f83e57aa |
| 関連情報 |
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関連タイプ |
isVersionOf |
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識別子タイプ |
DOI |
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関連識別子 |
https://doi.org/10.1088/1361-648X/adc060 |
| 収録物識別子 |
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収録物識別子タイプ |
EISSN |
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収録物識別子 |
1361-648X |
| 書誌情報 |
en : Journal of Physics: Condensed Matter
巻 37,
号 19,
p. 193001,
発行日 2025-05-12
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| ファイル公開日 |
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日付 |
2026-05-12 |
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日付タイプ |
Available |
JPCM_Kimizuka.pdf (1.8 MB)
