在La0.7Ce0.3Fe11.5Si1.5水化物中通过减小颗粒大小来减少歇斯底里
Mitali Madhusmita Prusty1, Sri Harsha Molleti1,2, Hiroto Takanobu3
1Green Magnetic Material Group, Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Japan.
Science and technology of advanced materials
|August 1, 2025
概括
微结构工程显著减少了LaCe(Fe,Si) 13Hx材料中的磁性歇斯底里. 通过融炼精炼前体合金可以创建更多的粒度边界,降低相位过渡的能量屏障,提高磁热冷却效率.
科学领域:
- 材料科学 材料科学 材料科学
- 热力学是一种热力学.
- 应用物理 应用物理
背景情况:
- 磁性冷却利用磁热效应 (MCE) 作为传统制冷的节能和环保替代方案.
- 磁热性材料中的大型磁性歇斯底里阻碍了高效的循环性能,限制了实际应用.
研究的目的:
- 研究降低La0.7Ce0.3(Fe,Si) 13Hx中的磁性歇斯底里斯的方法,这是一个有希望的材料,用于室温磁性制冷.
- 探索前体合金微结构对磁热性质和歇斯底里损失的影响.
主要方法:
- 使用常规技术和炼技术制备La0.7Ce0.3(Fe,Si) 13Hx前体合金.
- 使用洛伦茨传输电子显微镜 (Lorentz-TEM) 进行材料微观结构的表征.
- 使用现场X射线衍射分析相位过渡行为和hysteresis的分析.
主要成果:
- 与传统方法相比,炼前体合金显著降低了磁性歇斯底里.
- 融材料中的更细粒度结构提供了更高的粒度边界密度,作为优选的核化地点.
- 在融旋转化物中观察到减少的核化能量障碍和减弱的磁结构相位过渡,从而导致较低的歇斯底里损失.
结论:
- 微结构工程,特别是通过融,是一种有效的策略,以最大限度地减少 (La,Ce) ((Fe,Si) 13Hx材料中的歇斯底里.
- 优化谷物边界密度对于提高磁热材料在室温制冷中的性能至关重要.
- 这项工作表明了开发具有提高效率和减少能量损失的先进磁热材料的潜力.
相关概念视频
01:19Acid Halides to Alcohols: LiAlH4 Reduction
3.1K
Acid halides are reduced to alcohols in the presence of a strong reducing agent like lithium aluminum hydride.
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
3.1K
01:17Esters to Alcohols: Hydride Reductions
3.8K
Esters are reduced to primary alcohols when treated with a strong reducing agent like lithium aluminum hydride. The reaction requires two equivalents of the reducing agent and proceeds via an aldehyde intermediate.
Lithium aluminum hydride is a source of hydride ions and functions as a nucleophile. The mechanism proceeds in three steps. Firstly, the nucleophilic hydride ion attacks the carbonyl carbon of the ester to form a tetrahedral intermediate. Subsequently, the carbonyl group re-forms,...
Lithium aluminum hydride is a source of hydride ions and functions as a nucleophile. The mechanism proceeds in three steps. Firstly, the nucleophilic hydride ion attacks the carbonyl carbon of the ester to form a tetrahedral intermediate. Subsequently, the carbonyl group re-forms,...
3.8K