强烈的晶格软化是由原子不匹配引起的,在元相热电学中
Kunpeng Zhao1, Min Li2,3,4, Hexige Wuliji1
1State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Advanced science (Weinheim, Baden-Wurttemberg, Germany)
|October 6, 2025
概括
研究人员通过在元相中通过原子不匹配来降低声子速度来降低晶格导热率 (κL). 这种方法提高了热电性能,为设计先进的热电材料提供了新的策略.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 热电学是一种热电学.
背景情况:
- 减少格子导热率 (κL) 的传统方法依赖于具有固有的局限性的声子散射.
- 减少声平均自由路径是一个关键策略,但受到原子间距和声波长的限制.
研究的目的:
- 通过降低声子速度来抑制格子导热率 (κL) 的新策略.
- 研究原子不匹配对特定元相中的晶格导热率和热电性能的影响.
主要方法:
- 在Ag8SnS6,Cu2S和Mg2Si的晶格中包含具有显著原子不匹配的原子.
- 在Ag8SnS6和Cu2S中替代了硫 (S) 的 (Te),在Mg2Si中替代了 (Si) 的锡 (Sn).
- 分析了增加原子质量和削弱化学键对声速和晶格导热率 (κL) 的影响.
主要成果:
- 由于原子不匹配,声速显著降低,导致无形状的,在所有温度下极低的晶格导热率 (κL).
- 证明了卓越的热电性能,最大功率 (zT) 值为:Ag8SnS4.99Te的1.0,Mg2Si0.5Sn0.5的1.1和Cu2S0.5的2.0.
结论:
- 这项研究成功地展示了一种通过晶格软化来操纵导热的新方法.
- 这种方法为设计高性能热电材料提供了一个有希望的途径,通过有效降低晶格导热率 (κL).
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