Tl-Pb-Sr-Ca-Cu-Oシステムでは,最大122Kまでのバルク超伝導性が示されています
Science (New York, N.Y.)
|October 14, 1988
まとめ
バリウムを除く新しいタリウム-銅酸化物超伝導体が合成されました. これらの新材料は,120Kまでの高い臨界温度 (T) を表し,高度な超伝導アプリケーションの可能性を秘めています.
科学分野:
- マテリアルサイエンス 材料科学
- 固体物理 固体物理学
- 無機化学 無機化学とは
背景:
- 高温超伝導体の開発は,エネルギーと技術にとって極めて重要です.
- 酸化物超伝導体,特に銅を含む超伝導体は,著しく有望であることが示されています.
- 以前の研究は,バリウムを含むコプレートに重点を置いていたため,代替組成の探求が必要となった.
研究 の 目的:
- 新しい高温超伝導体を合成し,特徴づけること.
- バリウムを含まないタリウム銅酸化物を調査するために.
- これらの新しい材料の超伝導特性,特に臨界温度 (T) を決定する.
主な方法:
- オキシード材料を準備するために,固体合成技術が採用されました.
- 構造分析と相識別のためにX線 difraktion (XRD) が使用されました.
- 超伝導的移行温度 (T ((c)) を決定するために,電気抵抗性測定が行われました.
主要な成果:
- バリウムを含まない,タリウムと銅酸化物に基づく新しい超伝導材料が成功裏に製造されました.
- 化合物 (Tl{0.5}Pb{0.5}) Sr{2}CaCu{2}O{7}) はT{c}約85Kを示した.
- 化合物 (Tl{0.5}Pb{0.5}) Sr{2}Ca{2}Cu{3}O{9}) は,T{c) が約120Kであることを示した.
- 両方の材料は,XRDによって決定される特定の格子パラメータを持つ四角形構造で結晶化しました.
- シングルクリスタルX線 difraktionデータにより,上位T (c) 段階の詳細な構造精細化が可能になりました.
結論:
- バリウムのないタリウム・銅酸化物超伝導体の成功合成は,既知の高T (c) 材料のファミリーを拡大する.
- これらの新しい化合物で最大120KのT (c) 値を達成することは,実用的な応用の可能性を強調しています.
- 構造的特徴は,これらのシステムの組成,構造,および超伝導性の関係に関する基本的な洞察を提供します.
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