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arXiv 2108.06016cond-mat.soft
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局域结构在形变玻璃增强动力学中的作用

The Role of Local Structure in the Enhanced Dynamics of Deformed Glasses

Entao Yang, Robert A. Riggleman

摘要:

外加应力可以使非晶态固体的分子迁移率提高几个数量级。流动性的变化通常通过Eyring模型来解释,该模型调用了一个经验激活量,其起源仍然知之甚少。在这里,我们分析了恒定应力分子动力学模拟,并提出了一个扩展的Eyring模型与机器学习领域,软。我们的模型将激活体积(一个经验参数)与结构属性(柔软度)联系起来。我们发现,应力有一个不均匀的影响,取决于当地的结构,这解释了应力下观察到的弛豫时间分布较窄的流动性。

英文摘要:

External stress can accelerate molecular mobility of amorphous solids by several orders of magnitude. The changes in mobility are commonly interpreted through the Eyring model, which invokes an empirical activation volume whose origin remains poorly understood. Here, we analyze constant-stress molecular dynamics simulations and propose an extension of the Eyring model with a machine-learned field, softness. Our model connects the activation volume, an empirical parameter, to a structural property (softness). We show that stress has an inhomogeneous effect on the mobility that depends on local structure, which explains the narrower distribution of relaxation time observed under stress.

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。

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