Unusual volume reduction in CaLi2-xMgx by hydrogen uptake

• 資料種別: 記事
• タイトル: Unusual volume reduction in CaLi2-xMgx by hydrogen uptake
• 著者・編者: Hyunjeong Kim; Kouji Sakaki; Kohta Asano
• 出版事項: 日本 : 高輝度光科学研究センター
• 出版年月日等: 2020-01-22
• 出版年（W3CDTF）: 2020-01-22
• タイトル（掲載誌）: SPring-8/SACLA利用研究成果集
• 巻号年月日等（掲載誌）: 8(1)
• 掲載巻: 8(1)
• ISSN（掲載誌）: 2187-6886
• ISSN-L（掲載誌）: 2187-6886
• 本文の言語コード: eng
• DOI: 10.18957/rr.8.1.17; https://doi.org/10.18957/rr.8.1.17
• 国立国会図書館永続的識別子: info:ndljp/pid/11670498; https://dl.ndl.go.jp/pid/11670498
• コレクション（共通）: 障害者向け資料
• コレクション（障害者向け資料：レベル1）: テキストデータ
• コレクション（個別）: 国立国会図書館デジタルコレクション > 電子書籍・電子雑誌 > その他; https://dl.ndl.go.jp/collections/B00035
• 収集根拠: オンライン資料収集制度
• 受理日（W3CDTF）: 2021-05-13T20:29:08+09:00
• 保存日（W3CDTF）: 2020-03-25
• 記録形式（IMT）: application/pdf
• オンライン閲覧公開範囲: 国立国会図書館内限定公開
• デジタル化資料送信: 図書館・個人送信対象外
• 遠隔複写可否（NDL）: 可
• 掲載誌（URI）: https://user.spring8.or.jp/resrep/
• 掲載誌（国立国会図書館永続的識別子）: info:ndljp/pid/11670493; https://dl.ndl.go.jp/pid/11670493
• 連携機関・データベース: 国立国会図書館 : 国立国会図書館デジタルコレクション; https://dl.ndl.go.jp

• 要約等: To understand the hydrogen storage properties of CaLi_2-xMg_x having a C14 Laves phase structure, changes in its average and local structures by hydrogenation were investigated by using the Rietveld and the atomic pair distribution function analyses of X-ray diffraction data. We found that after hydrogen uptake at 283 K, Mg-containing samples exhibit a C14 phase with reduced volume. This C14 phase readily decomposes into CaH₂ at temperatures higher than 300 K. Our study suggests that hydrogen absorption in CaLi_2-xMg_x at 283 K is multi-step reaction. Lithium that can easily diffuse through C14 crystals reacts with hydrogen forming a Li-rich hydride phase. On the other hand, slow diffusion of large Ca atoms and strong Mg-Mg and Mg-Ca interaction restrain the immediate formation of CaH₂. As a result, there is a substantial time lag between the formation of a Li-rich hydride phase and the formation of CaH₂ at 283 K. This brings about a C14 phase with reduced volume where a large number of Li vacancies are present immediately after hydrogenation.
• DOI: 10.18957/rr.8.1.17
• オンライン閲覧公開範囲: インターネット公開
• 連携機関・データベース: 科学技術振興機構 : J-STAGE; http://www.jstage.jst.go.jp

• 要約等: To understand the hydrogen storage properties of CaLi_2-xMg_x having a C14 Laves phase structure, changes in its average and local structures by hydrogenation were investigated by using the Rietveld and the atomic pair distribution function analyses of X-ray diffraction data. We found that after hydrogen uptake at 283 K, Mg-containing samples exhibit a C14 phase with reduced volume. This C14 phase readily decomposes into CaH₂ at temperatures higher than 300 K. Our study suggests that hydrogen absorption in CaLi_2-xMg_x at 283 K is multi-step reaction. Lithium that can easily diffuse through C14 crystals reacts with hydrogen forming a Li-rich hydride phase. On the other hand, slow diffusion of large Ca atoms and strong Mg-Mg and Mg-Ca interaction restrain the immediate formation of CaH₂. As a result, there is a substantial time lag between the formation of a Li-rich hydride phase and the formation of CaH₂ at 283 K. This brings about a C14 phase with reduced volume where a large number of Li vacancies are present immediately after hydrogenation.
• DOI: 10.18957/rr.8.1.17; https://doi.org/10.18957/rr.8.1.17
• 関連情報（URI）: http://id.ndl.go.jp/digimeta/11670498; https://dl.ndl.go.jp/pid/11670498
• 連携機関・データベース: 国立情報学研究所 : CiNii Research; https://cir.nii.ac.jp/
• 提供元機関・データベース: Japan Link Center; https://japanlinkcenter.org/top; 雑誌記事索引データベース; https://ndlsearch.ndl.go.jp; CiNii Articles
• 書誌ID（NDLBibID）: 11670498; http://id.ndl.go.jp/bib/11670498
• NII論文ID: 130007969643