超伝導体YBa2Cu3O7の第2の液体渦相への異常な相変化
F Bouquet1, C Marcenat, E Steep
1Département de Recherche Fondamentale sur la Matière Condensée, Service de Physique, Magnétisme et Supraconductivité, CEA-Grenoble, 38054, Grenoble, France. Frederic_Bouquet@Yahoo.Com
Nature
|May 25, 2001
まとめ
研究者は,イットリウムバリウム銅酸化物 (YBa2Cu3O7) 超伝導体における渦輪相を研究した. 彼らは,臨界点より上にある反転可能な二次移行を発見し,新しい渦流液相を示した.
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
- 超伝導性は超伝導性である.
背景:
- 超伝導体は,磁場が渦を通り抜け,抵抗力に影響を及ぼします.
- 高温超伝導体では,渦が固体から液体状態に移行し,抵抗を引き起こします.
- イットリウムバリウム銅酸化物 (YBa2Cu3O7) で融解する渦の臨界点と熱力学的性質は不明である.
研究 の 目的:
- イットリウムバリウム銅酸化物 (YBa2Cu3O7) 超伝導体の相図を解明する.
- 臨界点の近くおよびその上にある渦の融解の熱力学的性質を調査する.
- 高磁場で発生する相変化を特徴付けるために.
主な方法:
- 特定の熱の測定. 特定の熱の測定. 特定の熱の測定. 特定の熱の測定.
- マグネチゼーションの測定.
- 26テスラまでの相図の探査.
主要な成果:
- イットrium Barium Copper Oxide (YBa2Cu3O7) の相図は26Tまで決定されました.
- 臨界点より上には,反転可能な第2次相移行が確認された.
- 高温相はより低い対称性を示し,理論的な予測と一致する.
結論:
- この研究は相図を確立し,YBa2Cu3O7.7の渦状態における二次変異を明らかにした.
- この発見は,第二の渦流液相への移行に関する理論的予測を裏付けている.
- この研究は,強力な磁場下での高温超伝導体の複雑な相行動を説明しています.
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