混合无形碳的稳定性及其转化为纳米钻石
Yifan Zhao1,2, Chao Zhao3, Xiao Wang1,2
1Institute of Technology for Carbon Neutrality, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
Small methods
|April 29, 2025
概括
由于钻石形成的高核能障碍,完全sp3-混合的无形碳 (sp3-AC) 是动态稳定的. 化产生一个sp-AC-纳米钻石复合物,一个中间材料.
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
- 计算化学计算化学
背景情况:
- 完全sp3-混合无形碳 (sp3-AC) 是一种具有重大研究兴趣的新型碳全方位.
- 了解其结构稳定性和演变,特别是其转化为钻石,至关重要.
研究的目的:
- 通过分子模拟来研究sp3-AC稳定的起源.
- 探索从sp3-AC到钻石的结构转变途径.
- 为了阐明形成sp-AC-纳米钻石复合材料背后的机制.
主要方法:
- 利用利用机器学习力场的分子模拟.
- 在sp3-AC结构中分析了碳扩散率.
- 计算了sp3-AC.内的钻石形成的核化能量屏障.
主要成果:
- 在sp3-AC中碳扩散极为缓慢,有助于动力稳定.
- 在sp3-AC内部的钻石核化在热力学上是不利的,原因是高核化能量屏障 (≈17 eV).
- 钻石核化诱导局部密度降低,抑制进一步的生长.
结论:
- 高核化能量屏障和密度降低机制解释了sp-AC的动力稳定性.
- 在高温和高压下对sp-AC进行火,产生了带有嵌入纳米钻石的sp-AC复合物.
- 这种sp3-AC-纳米钻石复合物代表无形碳和钻石之间的中间状态,解释了最近的实验发现.
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