2021年6月
Two distinct non-Arrhenius behaviors of hydrogen diffusivities in fcc aluminum, silver, and copper determined by ab initio path integral simulations
PHYSICAL REVIEW MATERIALS
- ,
- 巻
- 5
- 号
- 6
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1103/PhysRevMaterials.5.065406
- 出版者・発行元
- AMER PHYSICAL SOC
Nuclear quantum effects (NQEs) are highly important for understanding a host of kinetic processes that occur with the participation of H (e.g., H adsorption, diffusion, permeation, and trapping in materials). In this paper, ab initio path integral molecular dynamics simulations were used to investigate NQEs on the lattice diffusion of H in common face-centered cubic (fcc) metals such as Al, Ag, and Cu over a wide temperature range of 75-1200 K (75-900 K for Al). We determined that the dependence of H diffusivities on temperature in Ag and Cu has a "reversed-S" shape on Arrhenius plots, as confirmed for fcc Pd in our recent study [H. Kimizuka et al., Phys. Rev. B 100, 024104 (2019)]. This result illustrates that the phenomenon is common in many fcc metals in which H atoms prefer to occupy octahedral sites. On the other hand, in the case of Al, in which H atoms prefer to occupy tetrahedral sites, the dependence of H diffusivities on temperature exhibits a familiar "C" shape. Such counterintuitive behavior is ascribed to differences in the dependence on temperature of the activation barriers for H migration between both types of fcc metals; this is due to the NQEs involving a competition between deceleration of H migration, which becomes effective at high temperatures because of zero-point vibrations, and acceleration of H migration, which becomes effective at low temperatures because of quantum tunneling. The dominance of the two mechanisms is determined by the coupling of the NQEs and the site preference of H depending on the metal. This finding has important implications for the interpretation of kinetic processes involving the crossover from classical to quantum behavior of H atoms jumping between different types of interstitial sites.
- リンク情報
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- DOI
- https://doi.org/10.1103/PhysRevMaterials.5.065406
- Web of Science
- https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000669054200004&DestApp=WOS_CPL
- Scopus
- https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85109085580&origin=inward
- Scopus Citedby
- https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85109085580&origin=inward
- ID情報
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- DOI : 10.1103/PhysRevMaterials.5.065406
- ISSN : 2475-9953
- eISSN : 2475-9953
- SCOPUS ID : 85109085580
- Web of Science ID : WOS:000669054200004