在极端非平衡状态下,金属的异质化
Qiyu Zeng1,2,3, Xiaoxiang Yu4,5,6, Bo Chen1,2,3
1College of Science, National University of Defense Technology, Changsha, Hunan, China.
Nature communications
|November 25, 2025
概括
超快激光驱动金属的非热化,通过创建电子压力,导致在平衡温度以下的固体-液体界面的快速传播. 这种热电子效应为激光物质相互作用提供了新的见解.
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
- 激光-物质相互作用
背景情况:
- 激光激发会产生极端的电子离子不平衡状态,导致与热平衡区别的不明解化过程.
- 关于激光诱导化的传统理解是基于热平衡模型,这些模型不能完全捕捉超快现象.
研究的目的:
- 在极端的电子离子不平衡条件下研究激光诱导金属化的基本机制.
- 为了确定电子压力在超快激光激发过程中异质相变的作用.
主要方法:
- 利用神经网络增强的多尺度模拟用于和金纳米膜.
- 分析了电子压力松及其对相位转换的影响.
- 模拟时间解析的X射线衍射以区分非热和热膨胀.
主要成果:
- 识别了电子压力松作为异质相变的关键.
- 证明非热膨胀导致在平衡温度以下的表面发起的化.
- 观察到电子压力驱动的固体-液体接口在2500m/s的传播速度,比热机制快得多.
- 使用模拟的X射线衍射特征,区分非热膨胀和热膨胀.
结论:
- 已确立热电子介导的晶格不稳定是激光诱导结构转变的通用途径.
- 为解释时间解析的实验数据提供了新的见解.
- 通过了解非热融路径,开辟了控制激光物质相互作用的途径.
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