ドーピング不足の鉄アルセニド超伝導体における平面内抵抗性アニソトロピー
Jiun-Haw Chu1, James G Analytis, Kristiaan De Greve
1Department of Applied Physics and Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA 94305, USA.
Science (New York, N.Y.)
|August 14, 2010
まとめ
鉄アルセニドの高温超伝導性は,対称性破裂と関連しています. 研究者らは,Ba ((Fe,Co) 2As2) 結晶で電子アニソトロピーを発見し,ネマティック性と超伝導性についての洞察を明らかにしました.
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
- 固体化学 固体化学
背景:
- 高温超伝導は,対称性を破る基底状態の近くで頻繁に発生します.
- 鉄アルセニドでは,反鉄磁性と構造的な歪みにより,C ((4) 回転対称性が破られ,超伝導性の近くで共存する.
研究 の 目的:
- 電子アニソトロピーを研究するために,単一結晶のBa (Fe) 1 (x) Co (x) 2 (x) 2 (As) 2を研究する.
- 構造的移行,電子アニソトロピー,および鉄アルセニドにおける超伝導性の関係を理解する.
主な方法:
- 双子化した単結晶のBa (((Fe (((1-x)) Co (((x)) (((2) As (((2) の平面内抵抗力の測定.
- 構造変遷以上の温度で単軸張力を適用する.
主要な成果:
- 有意な電子アニソトロピーが観察され,b軸 (rho (b)) 沿いの抵抗はa軸 (rho (a)) 沿いの抵抗よりも大きい.
- アニソトロピーは,超伝導ドームの発生近くで最大値約2に達した.
- 単軸張力によって誘発された抵抗性アニソトロピーは,構造的移行の上のもので,実質的なネマティック感受性を示す.
結論:
- この研究は,構造的移行に関連したBa{\Fe}{\1-x}Co{\x}{\2}As{\2}の強い電子アニソトロピーを明らかにしています.
- このアニソトロピーは,鉄基材料における高温超伝導性のメカニズムを理解する上で重要な要因であるネマティック性に関連しています.
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