低圧で分子スピン・クロスオーバー・コンプレックスにおけるバロカロリー効果の駆動
Jinyoung Seo1, Jason D Braun1, Vidhya M Dev1
1Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States.
Journal of the American Chemical Society
|April 1, 2022
まとめ
圧力の誘発によるスピン・クロスオーバーによる分子鉄複合体において,巨大なバロカロリー効果が観察された. この発見は 効率的な固体冷却剤の開発に 有望な経路を示しています
科学分野:
- 材料科学
- 熱力学について
- 固体物理学
背景:
- 固体冷却剤の可能性を示しています.
- 効率的なバロカロリー冷却には,小さな圧力変化によって引き起こされる高エントロピー,可逆的な固体相移行を持つ材料が必要です.
研究 の 目的:
- Fe[HB(tz) 3 2における圧力誘発のスピン・クロスオーバー (SCO) 移行を,高熱効果のために調査する.
- リガンドデュテレーションによるSCOトランジション熱力学の調節性を探求する.
主な方法:
- 熱変化を測定する高圧カロメトリー
- 圧力による相変化を研究するための粉末X線 difraktion.
- トリゾルボラートリガンドの系統的なデュテレーション.
主要な成果:
- 10バーの低圧で 逆転するエントロピーの変化が起こります
- 150バーの圧力シフトは,巨大な同熱エントロピー変化 (> 90 J kg-1 K-1) とアディアバティック温度変化 (> 2 K) をもたらした.
- SCOの熱力学を うまく調整した
結論:
- Fe[HB(tz) 3 2の圧力誘発SCO移行は,アクセス可能な圧力で有意な熱量効果を引き起こす.
- 次世代の固体冷却剤の有望な候補です
- バロカロリー性能を最適化するための経路を提供する.
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