超伝導性は,鉄基の層状化合物LaO{1-x) F{-x) FeAsの43Kでの超伝導性である
Hiroki Takahashi1, Kazumi Igawa, Kazunobu Arii
1Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan. hiroki@chs.nihon-u.ac.jp
Nature
|April 25, 2008
まとめ
フッ素を添加したLaOFeAs超伝導体に圧力をかけると,その臨界温度 (T (c)) が著しく上昇します. この研究は,鉄オキシプニクチドを高温超伝導性の発見のための有望な新しいプラットフォームとして強調しています.
科学分野:
- 凝縮物質物理学 凝縮物質物理学
- マテリアルサイエンス 材料科学
- 超伝導性は超伝導性である.
背景:
- LaOFePやLaONiPのような鉄とニッケルベースの層状化合物は,低温の超伝導性を示しています.
- LaOFeAs (LaO{1-x}F{x}FeAs) にフッ化物をドーピングすることで,その超伝導的移行温度 (T{c}) が約26Kまで上昇した.
- これらの材料の超伝導性は,しばしば磁気不安定と関連しており,T (c) はキャリアドーピングと電荷移転の影響を受けます.
研究 の 目的:
- フッ素を添加したLaOFeAsの超伝導的移行温度 (T(c)) に対する外部圧力の影響を調査する.
- より高い超伝導的過渡温度を達成するための材料プラットフォームとして,層状の鉄オキシプニクチドの潜在能力を探求する.
主な方法:
- フッ素を添加したLaOFeAsのサンプルに外部圧力を施す実験.
- 異なる圧力条件下での超伝導的移行温度 (T(c)) の測定.
- 鉄オキシプニクチドにおける圧力,電荷移転,超伝導性の関係に関する分析.
主要な成果:
- 圧力の上昇は,F-ドーピングされたLaOFeAsの発症T (c) の急激な上昇につながった.
- 約4GPaで約43Kの最大T (c) が達成されました.
- これは,銅ベースの高T (c) 超伝導体を除いて,これまでに報告された最高T (c) 値の1つを表しています.
結論:
- 外圧は,フッ素を添加したLaOFe.As.の超伝導性を著しく高めます.
- アシオンの圧縮性と充電伝達の強化は,圧力によって引き起こされるT (c) 増加に寄与する.
- 層状鉄オキシプニクチド (LnOTMPn) は,新しい高温超伝導体を発見するための有望な材料プラットフォームを提供します.
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