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Updated: Jul 5, 2025
07:03
Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals
Published on: August 15, 2018
8.8K
多結晶EuB4O7化合物における巨大低場冷凍磁熱効果
Yuanpeng Wang1,2, Junsen Xiang3, Lei Zhang2
1School of Rare earths, University of Science and Technology of China, Hefei 230026, People's Republic of China.
Journal of the American Chemical Society
|January 23, 2024
まとめ
EuB4O7はヘリウム3冷却の代替品として優れた冷却性能を示しています. この化合物は,より低い温度とより長い冷却時間を達成し,アディアバティック消磁冷却に有望である.
科学分野:
- 材料科学
- 熱力学について
- 凝縮物質物理学
背景:
- ヘリウム3の資源は希少で高価で 代替冷却技術の探求を促しています
- アディアバティック脱磁冷却 (ADR) は,超低温を達成するための有望な代替手段です.
研究 の 目的:
- エウB4O7の磁気性および磁熱効果 (MCE) をADRアプリケーションで調査する.
- ヘリウム3の限界を乗り越えるための潜在的な冷媒としてEuB4O7を評価する.
主な方法:
- マグネティック・オーダリングを理解するための磁気測定
- 冷却性能を評価するための準アディアバティック解磁測定.
- 様々な磁場強度における磁気エントロピーの変化の分析.
主要な成果:
- EuB4O7は0.4K以上の磁気順を示せず,二極相互作用は約800mKです.
- 最大磁気エントロピーの変化は50 kOeで47.6 J·kg-1·K-1に達した.
- 最低温度は289mKで,商用冷媒Gd3Ga5O12 (GGG) を上回る.
- 2K環境で70分以上,700mK未満の冷却を継続する.
結論:
- EuB4O7は大きな磁熱効果と優れた冷却能力を有している.
- この化合物は,ADRのヘリウム-3の実行可能で高性能な代替品です.
- EuB4O7に関するさらなる研究により,超低温冷却技術が進歩する可能性があります.
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