広い温度範囲における酸化物多層電容器における大きな電熱効果
B Nair1, T Usui2, S Crossley1
1Department of Materials Science, University of Cambridge, Cambridge, UK.
Nature
|October 10, 2019
まとめ
先進的なヒートポンプでは,新しい電気カロリー材料によって,温度が大きく変化します. 高品質の多層電容器は,室温に近い5.5Kの温度シフトを達成し,既存の磁熱および電熱技術を改善します.
科学分野:
- 固体物理学
- 材料科学
- 熱力学
背景:
- 熱ポンプは,磁場と電場による磁熱効果と電熱効果を利用して冷却します.
- 現在のプロトタイプは,作業ボディの小さな温度変化 (<3K) によって制限され,実用的な性能を阻害しています.
- 既存の技術は永久磁石や高電圧に依存し,コストと大量に挑戦します.
研究 の 目的:
- 熱ポンプの性能を向上させる新しい電熱物質を実証する.
- PbSc0.5Ta0.5O3の多層電容器における電熱効果を調査する.
- 熱ポンプの設計を高度な電熱材料で再利用する可能性を調査する.
主な方法:
- PbSc0.5Ta0.5O3を用いた高品質の多層電容器の製造
- キュリー温度 (290 K) を超える超臨界電場 (29.0 V/μm) を適用して,鉄電相転換を推進する.
- ランダウ理論を用いた相変化の検証
- コンデンサの中央部で温度変化を測定する.
主要な成果:
- PbSc0.5Ta0.5O3コンデンサは,広い温度範囲で大きな電熱効果を発揮する.
- 室温に近いピーク温度の変化は5.5Kに達する.
- 176Kの範囲で3Kを超える温度変化が観測される.
- 第1次フェロ電動フェーズトランジションの超臨界走行が確認されました.
結論:
- 高品質のPbSc0.5Ta0.5O3の多層電容器は,重要な電気カロリー効果を示しています.
- これらの材料は,現在の磁熱および電熱の作業体に有望な代替品を提供します.
- 既存のマグネトカロリックヒートポンプをこれらのコンデンサに再利用すると,巨大な磁石なしで性能が向上する可能性があります.
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