在无形Fe-Y-Zr-B合金中出现的负热膨胀
Ming Gao1, Hankun Xu1, Kun Lin1
1University of Science and Technology Beijing, Institute of Solid State Chemistry, Department of Chemistry, Beijing 100083, China.
Physical review letters
|September 22, 2025
概括
研究人员在一个无形的铁----合金中发现了负热膨胀 (NTE). 在非晶体材料中观察到的这种不寻常的特性为先进材料的应用提供了新的可能性.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 磁力学 磁力学 是一种
背景情况:
- 负热膨胀 (NTE) 是一种罕见的现象,在像陶和金属有机框架这样的晶体材料中观察到.
- NTE涉及材料在加热时收缩,与典型的热膨胀相反.
研究的目的:
- 报告在无形合金中前所未有的NTE观测.
- 研究无形金属材料中NTE的起源和特征.
主要方法:
- 一种无形Fe_{87.5}Y_{3}Zr_{1.5}B_{8}合金的合成和表征.
- 在广泛的温度范围内测量热膨胀.
- 扩展的X射线吸收细结构 (EXAFS) 分析.
- 分析X射线对分布函数 (PDF) 分析.
主要成果:
- 在无形Fe_{87.5}Y_{3}Zr_{1.5}B_{8}合金中观察到一个前所未有的NTE.
- NTE现象是显著的,发生在广泛的温度范围 (200-375 K) 上,系数为α_{1}=-6.9×10^{-6} K^{-1}.
- 发现NTE是无形结构内在的,与铁磁矩相关.
- 在最接近邻居的Fe-Fe对中,EXAFS表示很强的NTE.
- PDF分析表明,无形合金中倾向于局部有序的原子排列.
结论:
- 无形合金代表了一种新型的材料类别,表现出NTE.
- 观察到的NTE是由局部结构,磁相互作用和热放松的复杂相互作用驱动的.
- 这一发现为科学研究和NTE材料的实际应用开辟了新的途径.
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