AlB2型前駆体AeGaE (Ae = Ca, Sr, Ba; E = Si, Ge, Sn) からのポリアニオンガリウム水化物
Michael J Evans1, Gregory P Holland, Francisco J Garcia-Garcia
1Department of Chemistry and Biochemistry, Arizona State University, P.O. Box 871604, Tempe, Arizona 85287-1604, USA.
Journal of the American Chemical Society
|August 14, 2008
まとめ
SrGaGeHのような新しい四分化水素は,金属間化合物から合成されました. これらの材料は,可逆的な金属非金属移行を示し,ユニークな2Dポリアニオン構造を特徴とし,材料科学における潜在的な応用があります.
科学分野:
- マテリアルサイエンス 材料科学
- 固体化学 固体化学
- 無機化学 無機化学とは
背景:
- アルカリ土金属 (Ae) - ガリウム (Ga) - プニクトゲン (E) インターメタル化合物 (Ae = Ca, Sr, Ba; E = Si, Ge, Sn) の水素化振る舞いを調査した.
- 前身フェーズであるAeGaEは金属特性を持ち,AlB2構造型またはその変種で結晶化します.
研究 の 目的:
- 式AeGaEH (D) の新型四分化水素 (デウテリド) を合成し,構造的に特徴づける.
- これらの新しいメイングループである金属/半金属ヒドリドの電子特性と水素貯蔵特性について調べる.
主な方法:
- インターメタリック前駆物の水素化による合成.
- 粉末X線 difraktion,ニュートロン difraktion,および固体 (1) H NMRスペクトロスコーピーを用いて構造的特徴づけ.
- バンドギャップ決定による電子プロパティ分析.
主要な成果:
- 成功してSrGaGeH(D),BaGaSiH(D),BaGaGeH(D,およびBaGaSnH(D) を取得しました.
- これらの水素は2D [GaEH](2-) ポリアニオンを特徴とする三角型SrAlSiH構造型で結晶化します.
- 小帯のギャップ (0.1-0.6 eV) が示され,水素化時に金属非金属への移行を示しています.
- SrGaGe,BaGaSi,BaGaGeの可逆金属非金属変異が観察されました; BaGaSnHは,水素の放出時に部分分解を示しました.
- 高い水素脱吸収温度 (>400 °C).
結論:
- 合成された四分化水素は,主要なグループである金属/半金属化合物の新しいクラスを表しています.
- [GaEH](2-) ポリアニオン構造と,その結果生じる電子特性は,重要な特徴である.
- 金属から非金属への移行の可逆性は,水素関連の応用の可能性を示唆しています.
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