混合イオン電子導体La2NiO4+δの酸化イオン移動性を固体 (17) O MAS NMRスペクトルで探知する
David M Halat1, Rıza Dervişoğlu1, Gunwoo Kim1
1Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
Journal of the American Chemical Society
|August 20, 2016
まとめ
この研究では,高度な固体MRIを用いて,パラマグネティック混合イオン電子導体 (MIEC) を分析し,固体酸化物燃料電池にとって不可欠なLa2NiO4+δにおける異なる酸素部位とその動きを明らかにした.
科学分野:
- 材料科学
- 固体化学
- スペクトロスコーピー
背景:
- 固体NMRはイオン導体の研究に不可欠です.
- 混合イオン電子導体 (MIEC) のパラマグネティック行動は,NMR分析を妨げます.
- La2NiO4+δは固体酸化物燃料電池 (SOFC) の主要な材料である.
研究 の 目的:
- パラマグネティックMIECのための高解像度 (17) O固体NMRを開発し,適用する.
- La2NiO4+δの酸素環境とダイナミクスを特徴づける.
- オキシードイオンダイナミクスを相変数に関連してモデル化します.
主な方法:
- 高解像度 (17) Oの固体NMRスペクトロシー
- 周期密度関数理論 (DFT) の計算
- マジック・アングル・ターニングとフェーズ調整サイドバンド分離 (MATPASS) NMR.
主要な成果:
- La2NiO4+δで3つの異なる酸素環境 (赤道,軸,間位) を特定した.
- 中間酸素による軸位置の構造的歪みが解消された.
- 約130°Cで,間接的酸化物の急速な動きと交換を観測した.
結論:
- MIECのパラマグネティック (17) O NMRとDFTの組み合わせ方法論を開発した.
- スペクトル時間スケールの酸化イオンダイナミクスのモデルを確立した.
- このアプローチは,様々なパラマグネット酸化物とMIECに適用できます.
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