LiFeAsの超伝導性特性の構成制御について
Michael J Pitcher1, Tom Lancaster, Jack D Wright
1Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, United Kingdom.
Journal of the American Chemical Society
|July 29, 2010
まとめ
LiFeAsの化学置換は,その超伝導性特性に大きく影響する. Li-欠乏は超伝導性を急速に抑制し,CoまたはNiの置換は臨界温度と超流体の硬さを低下させ,LiFeAsを強調します.
科学分野:
- 凝縮物質物理学 凝縮物質物理学
- 材料科学 材料科学とは
- 固体化学 固体化学
背景:
- リチウム鉄アルゼン化物 (LiFeAs) は,鉄基の優れた超伝導体である.
- 化学ドーピングが,その超伝導性特性に与える影響を理解することは,材料設計において極めて重要です.
研究 の 目的:
- LiFeAsの超伝導状態と結晶構造に,LiとFeの場所での化学置換の影響を調査する.
- 構成の変化と電子ドーピングに対するLiFeAsにおける超伝導性の感受性を決定する.
主な方法:
- 高解像度X線と中性子 difraktionによるX線と中性子 difraktionによる高解像度X線と中性子 difraktionによる中性子 difraktionによる高解像度X線と中性子 difraktionによる中性子 difraktionによる高解像度X線と中性子 difraktionによる中性子 difraktionによる高解像度X線と中性子 difraktionによる高解像度X線と中性子 difraktionによる高解像度X線と中性子 difraktionによる高解像度X線
- マグネトメトリー・マグネトメトリー
- ミオン-スピン回転スペクトロスコピー
主要な成果:
- Li-欠乏 (Li(1-y) Fe(1+y) As) は,超伝導性を急速に抑制し,y > 0.02で完全に破壊されます.
- FeをCoまたはNiに置き換えると,電子数が増加するにつれて,超伝導的移行温度 (T ((c)) と超流体硬度 (rho ((s)) が単調に低下します.
- 超伝導性は,より高いドーピングレベルでは完全に抑制されます.
- LiFeAs由来化合物は,他の鉄プニクチドよりも高い超流体硬さを示しています.
結論:
- LiFeAsの超伝導性は,化学組成とドーピングに非常に敏感です.
- T (c) と rho (s) の観測された傾向は,鉄基超伝導体のペアリングメカニズムについての洞察を提供します.
- LiFeAsは,その高い超流体硬度により,鉄のピニクチド超伝導体の中でユニークな位置を占めています.
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