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Atom Probe Tomography Studies on the Cu(In,Ga)Se2 Grain Boundaries
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ヴァレンス電子濃度による相変換:Gd5GaxGe4-xでスラブ間結合距離をチューニングする
Yurij Mozharivskyj1, Wonyoung Choe, Alexandra O Pecharsky
1Ames Laboratory, Iowa State University, Ames, Iowa 500110, USA.
Journal of the American Chemical Society
|December 5, 2003
まとめ
Gd(5) Ga(x) Ge(4-x) 化合物の結晶構造は,電子濃度に依存しています. より高い電子数はT-Tジマーを分解し,このガドリニウム合金システムの結晶構造を変更します.
科学分野:
- 固体化学 固体化学
- マテリアルサイエンス 材料科学
- クリスタログラフィーです.
背景:
- Gd(5) Ga(x) Ge(4-x) システムは,複雑な構造的行動を示しています.
- 構成,電子濃度,結晶構造の関係を理解することは,材料設計において極めて重要です.
研究 の 目的:
- Gd(5) Ga(x) Ge(4-x) システムの構造的進化を調査する.
- インタースラブT-Tダイマー距離と結晶構造に対するバレンスの電子濃度の影響を測定する.
主な方法:
- 単結晶と粉末のX線 difraktion研究.
- 緊密に結合する線形マフィン・ティン・オービタル (TB-LMTO) 計算.
主要な成果:
- 低 Ga 含有量 (x ≤ 0.6) と高電子濃度 (30.4-31 e-/formula) の相は,割れたインタースラブ T-T ダイマーを持つ Sm(5) Ge(4) 型構造を採用する.
- 含有量の高さ (1 ≤ x ≤ 2.2) と電子濃度の低さ (28.8-30 e-/formula) の高さを持つ相は,Pu(5) Rh(4) -またはGd(5) Si(4) -型の構造を表示し,インタースラブT-Tダイマーが無傷である.
- Gd(5) GaGe(3) に対して,中間のPu(5) Rh(4) 型構造が特定されました.
- 電子構造の計算によると,GaをGeに置き換えることで,反結合状態の電子群が増加し,ダイマーが伸縮し,分裂する.
結論:
- バルエレクトロンの濃度は,Gd(5) Ga(x) Ge(4-x) システムにおける結晶構造とインタースラブT-Tダイマー形成を制御する重要な要因です.
- 観測された構造的移行は,電子帯の埋着の変化によって引き起こされ,T-T二次体内の結合に影響を与えます.
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