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酸素欠陥のペロブスキートLa2-xSrxCuO4-yの40Kでの超伝導性
Science (New York, N.Y.)
|March 13, 1987
まとめ
ランタン・ストロンチウム・銅酸化物化合物の超伝導性が調査されました. 最大移行温度 (Tc) の最適な条件は,ストロンチウム含有量と酸素熱解熱の調整によって見つかり,超伝導特性に逆転的に影響しました.
科学分野:
- 固体物理 固体物理学
- マテリアルサイエンス 材料科学
- 超伝導性に関する研究
背景:
- La2-xSrx CuO4-yは,有名なカップレート超伝導体ファミリーである.
- 組成,構造,および超伝導性特性の関係を理解することは,材料の開発において極めて重要です.
研究 の 目的:
- La2-xSrx CuO4-y化合物の構造,磁気,および電子特性を調査する.
- ストロンチウムドーピング (x) と酸素含有量 (y) が超伝導性,特に臨界温度 (Tc) に与える影響を決定する.
主な方法:
- 異なるストロンチウム含有量を持つLa2-xSrx CuO4-yシリーズの合成と特徴付け.
- 電気抵抗,磁気感受性,およびメイスナー効果の測定.
- 酸素と真空下で高温で冷却する研究.
主要な成果:
- 超伝導性は,La2-xSrx CuO4-y.のいくつかの組成で観察されました.
- x = 0.15 の場合,最大移行温度 (Tc) 39.3 K が達成され,狭い移行幅は 2 K でした.
- x = 0.15 のサンプルを酸素で冷却すると,Tc が 40.3 K に増加し,真空冷却では超伝導性が抑制され,これらの変化は可逆であった.
結論:
- ストロンチウムドーピングと酸素ステキオメトリーは,La2-xSrx CuO4-y.の超伝導特性に大きな影響を与える.
- 解熱による酸素含有量の最適化は,これらの材料の臨界温度を高めるための有効な方法です.
- 観測された可逆的な変化は,酸素ステキオメトリーに対する超伝導性の感受性を強調しています.
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