Behavior of vacancy formation and recovery during hydrogenation cycles in LaNi4.93Sn0.27

Kouji Sakaki, Ryosuke Date, Masataka Mizuno, Hideki Araki, Yumiko Nakamura, Yasuharu Shirai, Robert C. Bowman, Etsuo Akiba

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

To clarify the effect of substitution of Sn for Ni of LaNi5 on cyclic durability of hydrogen storage, the behavior of lattice defects during the hydrogenation cycles at 288 K in LaNi4.93Sn0.27 was investigated by in situ positron lifetime measurements. Mean positron lifetime increased to 175 ps by vacancy formation during initial hydrogenation and then decreased to 135 ps by vacancy recovery during dehydrogenation. Vacancies were reversibly introduced and removed at 288 K, although quenched-in vacancy cannot migrate below 448 K in LaNi4.93Sn0.27. Reversible change of the positron lifetime was observed in subsequent cycles, and dislocation density and vacancy concentration remained almost constant at around 6 × 109 cm-2 and 10 ppm, respectively, which are two orders of magnitude lower than those in binary LaNi5. These results indicate that the degradation of hydrogen capacity during a cycle closely relates to the concentration of lattice defects accumulated with hydrogenation.

Original languageEnglish
Pages (from-to)205-211
Number of pages7
JournalJournal of Alloys and Compounds
Volume477
Issue number1-2
DOIs
Publication statusPublished - May 27 2009

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Hydrogenation
Vacancies
Positrons
Recovery
Crystal defects
Hydrogen storage
Dehydrogenation
Dislocations (crystals)
Hydrogen
Durability
Substitution reactions
Degradation

All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Cite this

Sakaki, K., Date, R., Mizuno, M., Araki, H., Nakamura, Y., Shirai, Y., ... Akiba, E. (2009). Behavior of vacancy formation and recovery during hydrogenation cycles in LaNi4.93Sn0.27. Journal of Alloys and Compounds, 477(1-2), 205-211. https://doi.org/10.1016/j.jallcom.2008.10.058

Behavior of vacancy formation and recovery during hydrogenation cycles in LaNi4.93Sn0.27. / Sakaki, Kouji; Date, Ryosuke; Mizuno, Masataka; Araki, Hideki; Nakamura, Yumiko; Shirai, Yasuharu; Bowman, Robert C.; Akiba, Etsuo.

In: Journal of Alloys and Compounds, Vol. 477, No. 1-2, 27.05.2009, p. 205-211.

Research output: Contribution to journalArticle

Sakaki, K, Date, R, Mizuno, M, Araki, H, Nakamura, Y, Shirai, Y, Bowman, RC & Akiba, E 2009, 'Behavior of vacancy formation and recovery during hydrogenation cycles in LaNi4.93Sn0.27', Journal of Alloys and Compounds, vol. 477, no. 1-2, pp. 205-211. https://doi.org/10.1016/j.jallcom.2008.10.058
Sakaki, Kouji ; Date, Ryosuke ; Mizuno, Masataka ; Araki, Hideki ; Nakamura, Yumiko ; Shirai, Yasuharu ; Bowman, Robert C. ; Akiba, Etsuo. / Behavior of vacancy formation and recovery during hydrogenation cycles in LaNi4.93Sn0.27. In: Journal of Alloys and Compounds. 2009 ; Vol. 477, No. 1-2. pp. 205-211.
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