非添加剂混合对二元纳米晶超的热结合强度和相位行为的影响
Isabela Quintela Matos1, Fernando A Escobedo1
1F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, USA.
The Journal of chemical physics
|November 1, 2024
概括
体纳米颗粒中的无热相过渡是由非添加剂混合驱动的. 通过尺寸不对称性或颗粒隙实现的负非添加性,稳定了复合晶体的形成,影响了自由能量和压力.
科学领域:
- 材料科学 材料科学 材料科学
- 体科学 体科学 体科学
- 统计力学 统计力学
背景情况:
- 非添加剂混合显著影响分子流体和固体的散装性质.
- 在没有热波动的情况下发生的无热相过渡对于理解材料中的有序结构至关重要.
研究的目的:
- 调查非添加剂二元合纳米颗粒中超热秩序-混乱相位转换的可能性.
- 探索由大小不对称性和颗粒缩引起的负非添加性如何影响替代顺序化合物的形成.
主要方法:
- 利用蒙特卡洛模拟来准相位共存条件.
- 检查了八面体+球体 (CsCl晶格) 和立方体+球体 (NaCl晶体) 的等分体混合物.
- 通过组件尺寸不对称性和可调整尺寸的多面体内痕,具有不同程度的负面非添加性.
主要成果:
- 复合晶体的稳定需要相当大的负非附加性,这取决于粒子几何和相封装.
- 在大型球体和小的,非缩立方体的混合物中观察到负的非添加性和无热的NaCl晶格结晶.
- 立方体和球体的缩促进了相似大小的组件的热相对应过渡,更深的缩有利于更密集的NaCl相.
结论:
- 负非添加性是稳定二元合体系统中非热化合物相的一个关键因素.
- 颗粒几何,特别是痕,可以进行工程,以控制非添加性,并促进特定的晶体结构.
- 这项研究表明,通过精心设计的体混合物和成分相互作用,可以通过一种途径实现热结晶.
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