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液体金属中的静止原子及其在固化机制中的作用
Christopher Leist1,2, Sadegh Ghaderzadeh3, Emerson C Kohlrausch3
1Central Facility Materials Science Electron Microscopy, Ulm University, Ulm 89081, Germany.
ACS nano
|December 9, 2025
概括
液体金属纳米粒子可以包含静止的原子,挑战传统的相位过渡理解. 这些固定原子影响固化,使得超冷液体和无形固体在较低的温度下.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 物理化学 物理化学
背景情况:
- 液体和固体金属的区别传统上是基于原子运动.
- 固化涉及通过核化从无序转变为有序的原子结构.
- 在液体金属相中静止原子的作用仍然不太清楚.
研究的目的:
- 研究静止原子对金属纳米粒子固化路径的影响.
- 探索超冷液体金属的形成和无形固化.
- 了解纳米级核和相变的机制.
主要方法:
- 在低加速电压下利用了经过球形和色差偏差校正的高分辨率传输电子显微镜 (HRTEM).
- 开发了一种在广泛的温度范围 (20800°C) 中对金属纳米粒子进行原子分辨率成像的方法.
- 在冷却过程中对单个3-6nm,和金纳米粒子进行了时间序列成像和对比分析.
主要成果:
- 在液体金属纳米颗粒中确定了静止原子,在石墨烯基板上的空缺缺陷点上固定.
- 观察到静止原子的数量和排列决定了固化路径:少数随机原子促进核形成,而大量或周边对齐的原子抑制了结晶.
- 证明静止原子可以稳定液态纳米滴到200300°C,导致无形固化而不是结晶.
结论:
- 液体金属中静止原子的存在和行为显著改变了相变动力学.
- 静止原子可以诱导超冷却,并促进金属纳米粒子的无形固化.
- 这些发现对异质催化和热过程具有影响,这些过程涉及碳支上的金属纳米粒子.
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