在Fe纳米集群中,以大小为依赖的二次相似相过渡从低温结构异构化融化而成
Louis E S Hoffenberg1, Alexander Khrabry1, Yuri Barsukov1
1Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08540, USA.
The Journal of chemical physics
|April 7, 2025
概括
这项研究探讨了铁 (Fe) 纳米集群化. 表面化发生在低于核心化的温度下,受集群结构和大小的影响.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学计算化学
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 纳米集群化的行为对于理解纳米级材料特性至关重要.
- 原子结构对金属集群中相变的影响尚未完全理解.
- 铁 (Fen) 纳米集群为研究这些现象提供了一个模型系统.
研究的目的:
- 为了研究Fen纳米集群 (10 ≤ n ≤ 100个原子) 的化相变.
- 为了确定集群结构,大小和融特性之间的关系.
- 分析表面与核心化的发生以及不同的过渡顺序.
主要方法:
- 使用了经典的多体分子动力学模拟.
- 计算了各种集群大小的点 (表面,核心和能量).
- 分析了热容量 (Cv),以确定过渡类型.
主要成果:
- 许多Fen纳米集群的表面化在明显低于核心化的温度下被观察到.
- 融特性强烈依赖于纳米集群的特定原子结构.
- 大约三分之一的研究集群大小表现出类似于二次阶段过渡的二次阶段过渡.
- 靠近封闭外结构的1-shell集群显示出不同的点行为.
- 在核心融化之前的表面融化在具有特定核心结构的较大集群 (>50个原子) 中被观察到.
结论:
- 纳米集群结构决定了融化行为,包括表面与核心融化和过渡顺序.
- 封闭外结构有利于第一阶段的类似过渡,而接近封闭外结构可以表现出独特的化特征.
- 这些发现为金属纳米集群的基本相变物理提供了洞察力.
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