カップレート超伝導材料の電子構造とバレンスの結合帯構造
Science (New York, N.Y.)
|February 19, 1988
まとめ
高温超伝導体は,銅部位間の反鉄磁気結合を示す. CuO以外の酸化酸素原子は,CuO構造のジャンプする酸素穴を通って伝導性を促進します.
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
- 量子化学とは,量子化学である.
背景:
- カプレートにおける高温超伝導性は,依然として複雑な現象である.
- 電子構造と電荷媒体の理解は,超伝導性を説明する上で極めて重要です.
研究 の 目的:
- 超伝導体La2-xSrxCu(1) O(4) とY(1) Ba(2) Cu(3) O(7) の電子状態と電荷キャリア機構を調査する.
- 導電性における銅と酸素の酸化状態の役割を明らかにする.
主な方法:
- 代表的なクラスターモデルに関する Ab initio 計算.
- 電子構成とスピンカップリングの分析.
- チャージキャリア移行のための帯域構造の計算.
主要な成果:
- 銅部位は主にCu (II) 酸化状態で,反鉄磁気回転結合がある.
- Cu (II) を超える酸化は,Cu (II) 部位を橋渡しする酸化酸素原子 (酸素のピッピーホール) を生み出します.
- 酸素のppi穴は,隣接するCu (II) d電子と鉄磁気結合を示す.
- CuOシート/チェーンにおける酸素 ppiホールのジャンプは,電気伝導性のメカニズムとして特定されています.
結論:
- これらの超伝導体の電子構造は,Cu (II) 部位の局所的なスピンと,酸素の移動孔を含む.
- 銅と酸素の電子状態の相互作用が導電性特性を決定する.
- アブ・イニシオ・メソッドは,高温超伝導性の微小な起源についての洞察を提供します.
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