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Fabrication and Characterization of Superconducting Resonators
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(La0.5-xNa0.5+x) Fe2As2の穴ドーピング側における超伝導性
Akira Iyo1, Kenji Kawashima1,2, Shigeyuki Ishida1
1National Institute of Advanced Industrial Science and Technology (AIST) , 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
Journal of the American Chemical Society
|December 28, 2017
まとめ
研究者はポリクリスタリン (La,Na) 122のサンプルを合成し,ホールドーピング材料で大量超伝導性を達成しました. この研究では,これらの鉄基超伝導体の電子相図を調査し,最大移行温度を27.0Kとしました.
科学分野:
- 凝縮物質物理学
- 材料科学
- 超伝導性
背景:
- (La,Na) 122システムは,異なる組成 (x) によってFe2As2層の電子と穴のドーピング効果を研究するためのユニークなプラットフォームを提供します.
- 以前の合成の努力は,x = 0.1の非散発超伝導単体結晶に限られ,包括的な相図探査を妨げていた.
研究 の 目的:
- 多結晶 (La,Na) 122のサンプルを,幅広い穴ドーピング組成 (0 ≤ x ≤ 0.35) で合成する.
- 大量の超伝導性の出現を調査し, (La,Na) 122 システムのホールドーピング側の電子相図を構築する.
- Feベースの超伝導体における電子ドーピングサンプルを合成し,電子穴対称性を理解するための課題に取り組む.
主な方法:
- 従来の固体反応技術で,ドーピング成分xに基づいて反応温度を慎重に調整します.
- x = 0からx = 0.35までの穴ドーピング濃度のための多結晶サンプル合成
- 構造的および磁気的移行に関連する超伝導的移行と異常を特定するための抵抗性測定.
主要な成果:
- 穴ドーピング組成 0 ≤ x ≤ 0.35 の (La,Na) 122 のポリクリスタリンサンプルを成功して合成した.
- 元の化合物の抵抗性異常温度 (x = 0) は穴のドーピング増加とともに低下することが観察されました.
- 0.15 ≤x ≤0.35の範囲で発生する超伝導性が発見され,最大臨界温度 (Tc) はx = 0.3で27.0Kである.
- (La,Na) 122システムのホールドーピング側の電子相図を構成した.
結論:
- ホールドーピングされた多結晶 (La,Na) 122の試料は,温度を最適化することによって,固体反応で成功して合成することができる.
- 穴ドーピング (La,Na)122では,0.15 ≤ x ≤ 0.35で大量超伝導性が得られ,Tcは27.0Kであることが示される.
- 電子ドーピングされたサンプルを合成できないことは,非対称性を強調し,電子相図を完成させ,電子穴対称性を探求するためにさらなる研究を必要とします.
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