Nanostructures of hydrogen absorbing alloys

Etsuo Akiba, Hirotoshi Enoki, Yumiko Nakamura

研究成果: Chapter in Book/Report/Conference proceedingConference contribution


Hydrogen absorbing alloys expand and contract 20-30% in volume with hydrogenation and dehydrogenation, and this process causes defects in the alloy lattice. Studies on LaNi5 with in-situ x-ray diffraction and Rietveld analysis in combination with TEM imaging has demonstrated that the first hydrogenation reaction introduces a huge number of dislocations to the lattice but without a change in crystallite size. We also found that when a small amount of Ni in LaNi5 was replaced by other elements, the strain introduced during the first hydrogenation could be reduced or eliminated but different type of strain is introduced in the two-phase region. We have developed new hydrogen absorbing alloys with the BCC structure. The hydrogen capacity of these alloys reaches to almost double of conventional LaNi 5. As shown by TEM, the alloys exhibit a developed BCC modulated structure, with the width and thickness of each phase being 100-200 nm and about 10 nm, respectively. We propose that the strain through the coherent boundary in the modulated nano-order structure confers more hydrogen capacity upon these materials compared to those without a modulated nano-structure.

ホスト出版物のタイトルProcessing and Fabrication of Advanced Materials XII
編集者T.S. Srivatsan, R.A. Varin
出版ステータス出版済み - 12 1 2003
イベントProcessing and Fabrication of Advanced Materials XII - Pittsburgh, PA, 米国
継続期間: 10 13 200310 15 2003


名前Processing and Fabrication of Advanced Materials XII


その他Processing and Fabrication of Advanced Materials XII
CityPittsburgh, PA

All Science Journal Classification (ASJC) codes

  • 材料科学(全般)


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