Frechero M A, Alarcón L M, Schulz E P, Appignanesi G A
Fisicoquímica, Departamento de Química, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahía Blanca, Argentina.
Phys Rev E Stat Nonlin Soft Matter Phys. 2007 Jan;75(1 Pt 1):011502. doi: 10.1103/PhysRevE.75.011502. Epub 2007 Jan 9.
Dynamics in glass-forming liquids in the supercooled regime vary considerably from one point of the sample to another suggesting the existence of regions with different degrees of jamming. In fact, the existence of relatively compact regions with particles with an enhanced propensity for motion has been detected in model glassy systems. In turn, the structural relaxation has been shown to be accomplished by means of a series of fast transitions between metabasins in the potential energy landscape involving the collective motion of a substantial number of particles arranged in relatively compact clusters (democratic clusters or d clusters). In this work we shall complete this picture by identifying the connections between local structural jamming, metabasin confining strength, and d clusters. Thus we shall demonstrate that the degree of jamming of the local structure dictates the confining strength of the local metabasin and that the local high propensity regions and the d clusters are not only similar in nature but that they share a significant amount of particles.
在过冷状态下,玻璃形成液体中的动力学在样品的不同点之间变化很大,这表明存在不同程度的堵塞区域。事实上,在模型玻璃系统中已经检测到存在相对紧凑的区域,其中的粒子具有增强的运动倾向。反过来,结构弛豫已被证明是通过势能景观中代谢盆地之间的一系列快速转变来完成的,这些转变涉及大量排列在相对紧凑簇(民主簇或d簇)中的粒子的集体运动。在这项工作中,我们将通过确定局部结构堵塞、代谢盆地限制强度和d簇之间的联系来完善这幅图景。因此,我们将证明局部结构的堵塞程度决定了局部代谢盆地的限制强度,并且局部高倾向区域和d簇不仅本质相似,而且它们共享大量粒子。