arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2302.09549cond-mat.softcond-mat.dis-nncond-mat.mtrl-scicond-mat.stat-mech
收藏

多分散性对玻璃态液体弛豫机制的影响

Influence of polydispersity on the relaxation mechanisms of glassy liquids

Ilian Pihlajamaa, Corentin C. L. Laudicina, Liesbeth M. C. Janssen

AI总结:

本文研究尺寸多分散性对深度过冷液体弛豫动力学的影响,发现跨越模式耦合温度后小粒子与大粒子出现动力学分离,小粒子的笼逃逸促进大粒子的结构弛豫,且不同尺寸粒子表现出不同的Stokes-Einstein关系破坏程度和活化能势垒,强调推广结果时须考虑粒子尺寸效应。

摘要:

用于模拟深度过冷液体的最先进技术需要高度的尺寸多分散性才能有效。虽然这些技术使人们对玻璃转变附近的微观动力学有了深入认识,但大多分散性对动力学的影响在很大程度上仍未得到研究。在这里,我们表明粒子的尺寸不仅与其迁移率有很强的相关性,而且我们还观察到,当跨越模式耦合温度并且系统变得更加深度过冷时,在对应于笼逃逸的时间尺度上,出现了小的可移动粒子与较大的静止粒子之间的动力学分离。我们的结果表明,这一可移动粒子群体的笼逃逸促进了静止粒子随后的结构弛豫。在深度过冷区域中,我们表明不同尺寸的粒子表现出不同程度的Stokes-Einstein关系破坏,并具有不同的活化能势垒。总体而言,这表明在将结果推广到其他玻璃形成系统时,考虑粒子尺寸效应是重要的。

英文摘要:

State-of-the-art techniques for simulating deeply supercooled liquids require a high degree of size polydispersity to be effective. While these techniques have enabled great insight into the microscopic dynamics near the glass transition, the effect of the large polydispersity on the dynamics has remained largely unstudied. Here we show that a particle's size not only has a strong correlation with its mobility, but we also observe that, as the mode-coupling temperature is crossed and the system becomes more deeply supercooled, a dynamic separation between small mobile and larger quiescent particles emerges at timescales corresponding to cage escape. Our results suggest that the cage escape of this population of mobile particles facilitates the later structural relaxation of the quiescent particles. In the deep supercooled regime, we show that particles of different sizes display varying degrees of breakdown of the Stokes-Einstein relation and have different activation energy barriers. Overall, this indicates that it is important to account for particle-size effects when generalizing results to other glass-forming systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑