鉄基バイナリ・フェロマグネット
Akito Sakai1,2,3, Susumu Minami4,5, Takashi Koretsune6
1Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan.
Nature
|May 8, 2020
まとめ
研究者は,鉄にアルミニウムとガリウムをドーピングすることで,エネルギー収集のための異常なネルスト効果 (ANE) を強化しました. この突破は熱電性能と 柔軟な発電機の材料の可能性を高めます
科学分野:
- 材料科学
- 凝縮物質物理学
- 固体物理学
背景:
- 異常なネルスト効果 (ANE) を利用した熱電発電は,横断幾何学によりエネルギー収集の可能性を秘めています.
- ANEの性能,コスト,安全性,安定性を改善することは,実用的なアプリケーションにとって極めて重要です.
- ANEは,フェルミエネルギー近くの伝導電子のベリー曲線から発生します.
研究 の 目的:
- 異常なネルスト効果を 劇的に強化する材料を コンピューターで探す
- ANEの強化を担当する電子構造を調べる
- 低コストで柔軟な熱電発電機を開発する.
主な方法:
- アルファ鉄のドーパントの 計算式検索
- 電子構造とベリーの曲線を 調べている
- 実験的な検証のために薄膜を製造する.
主要な成果:
- アルファ鉄を25%のアルミニウムやガリウムで ドーピングすると ANEが10倍以上増加します
- 室温で1ケルビンあたり約4〜6マイクロボルトのANE値を達成した.
- 断面的熱電係数の強力な強化の鍵としてノードネットワークへのフェルミエネルギーチューニングを特定しました.
結論:
- ドーピングされた鉄は ANEを大幅に高め 記録的な値に近づいています
- 高性能なANEには,ノードネットワーク構造へのフェルミエネルギーチューニングが不可欠です.
- 製造された薄膜は低コストで柔軟な熱電発電機の可能性を示しています.
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