在铁电多晶体中以域墙驱动的抑制热导电性
Rachid Belrhiti-Nejjar1, Manuel Zahn2,3, Patrice Limelette1
1GREMAN UMR 7347, Université de Tours, CNRS, INSA-CVL, 15 rue de la chocolaterie, Blois, 41034, France.
Advanced science (Weinheim, Baden-Wurttemberg, Germany)
|July 25, 2025
概括
在不恰当的铁电ErMnO3多晶体中,随着颗粒大小的增加,导热性会下降. 这是由于在铁电域壁上的声子散射,而不是典型的粒度边界效应.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 固态化学 固态化学
背景情况:
- 降低多晶材料的导热性通常涉及增加粒度边界以增强声子散射.
- 这一策略广泛应用于各种材料类,包括金属,氧化物和像石墨烯这样的二维系统.
- 然而,微观结构和热传输之间的关系可以根据材料特性而有很大差异.
研究的目的:
- 为了研究不适当的铁电ErMnO3多晶体中颗粒大小和导热率之间的异常关系.
- 了解负责热传输和微观结构之间观察到的反向关系的潜在机制.
- 探索ErMnO3中微结构工程的潜力,用于先进的应用.
主要方法:
- 合成不同粒度的ErMnO3多晶体.
- 测量热导率作为温度和微观结构的函数.
- 对声子散射机制的分析,特别关注铁电域壁.
主要成果:
- 观察到一个反向关系:随着ErMnO3多晶体颗粒大小的增加,热导率下降.
- 将这种行为归因于在更大的粒度内的铁电域壁上增加了声子散射.
- 证明域壁密度,而不是谷物边界密度,在这个系统中主导热传输.
结论:
- 铁电域壁在ErMnO3中的声子散射中发挥着关键作用,逆转了传统的粒度边界效应.
- 微结构工程,特别是控制颗粒大小和域壁密度,为调整热性质提供了一种新的方法.
- 这些发现为设计用于热电和热管理应用的材料提供了新的途径.
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