RE2Ru3Ge5の新ポリモルフにおける電荷密度波 (RE = Pr, Sm, Dy)
Daniel E Bugaris1, Christos D Malliakas1,2, Fei Han1
1Materials Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
Journal of the American Chemical Society
|February 17, 2017
まとめ
新しい稀土ルテニウムゲルマニド化合物 (RE2Ru3Ge5) は,電荷密度波 (CDW) による低温構造転換を示している. この移行は,ゲルマニウム鎖の歪みと同時に電子状態の変化を含みます.
科学分野:
- 固体化学
- 材料科学
- クリスタルグラフィー
背景:
- 稀土 (RE) ルテニウムゲルマニド (RE2Ru3Ge5) は,金属間化合物として知られています.
- 材料の構造と電子的性質を理解することは 材料の設計において極めて重要です
研究 の 目的:
- RE2Ru3Ge5化合物の新しいポリモルフ (RE = Pr, Sm, Dy) を合成し,特徴づけること.
- 充電密度波 (CDW) に起因する低温構造的移行を調査する.
- 構造的移行と電子特性の関係を解明する.
主な方法:
- 単一結晶の成長はインジウム流量法を使用しています.
- 結晶構造 (高温と低温) の決定のためのX線 difraktion (XRD).
- 電荷輸送測定 (抵抗力,ホール効果,磁気抵抗)
- 磁気測定と熱容量分析
- X線吸収近辺光譜 (XANES) と電子帯域構造の計算
主要な成果:
- スク2Fe3Si5型のテトラゴナルP4 / mnc構造は,Pr,Sm,およびDy類型で確認されました.
- 負荷密度波 (CDW) に関する低温構造的移行が観察されました.
- Pr (~200 K) と Sm (~175 K) の化合物に対して,CDWオーダー温度 (TCDW) を決定した.
- 周期的なジグザグ型のGeチェーンがCDW状態を特徴づける.
- CDWの移行とともに同時に電子状態の移行が検出されました.
結論:
- 合成されたRE2Ru3Ge5化合物は,興味深い電子現象の可能性を持つ新しいポリモルフを表しています.
- 観測された電荷密度波の移行は,材料の性質に大きく影響します.
- 構造的歪みと電子状態の相互作用は これらのゲルマニドの基本的な物理に洞察を与えます
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