Roles of icosahedral and crystal-like order in the hard spheres glass transition
Roles of icosahedral and crystal-like order in the hard spheres glass transition
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DOI：
10.1038/ncomms1974
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发表时间：
2012-07-01
影响因子：
16.6
通讯作者：
Tanaka, Hajime
中科院分区：
文献类型：
--
作者：
Leocmach, Mathieu;Tanaka, Hajime
结构有序和慢动力学之间的联系最近引起了人们的广泛关注，从玻璃慢动力学的起源。这种结构顺序的候选者是二十面体，外来的无定形和晶体状。每种类型的顺序都与不同的玻璃化转变场景有关。在这里，我们实验访问多分散硬球的局部结构秩序的粒子级共聚焦显微镜。我们确定的关键结构为二十面体和FCC状的顺序，都与慢粒子统计。然而，当接近玻璃化转变时，二十面体有序的尺寸不会增长，而类晶体有序则会增长。正是后者支配着动态，并与动态异质性相联系。这一问题的直接作用的本地二十面体有序玻璃缓慢的动力学，并建议增长的长度规模的结构顺序是必不可少的动力学和非本地合作性粒子运动的减速。
A link between structural ordering and slow dynamics has recently attracted much attention from the context of the origin of glassy slow dynamics. Candidates for such structural order are icosahedral, exotic amorphous and crystal-like. Each type of order is linked to a different scenario of glass transition. Here we experimentally access local structural order in polydisperse hard spheres by particle-level confocal microscopy. We identify the key structures as icosahedral and FCC-like order, both statistically associated with slow particles. However, when approaching the glass transition, the icosahedral order does not grow in size, whereas crystal-like order grows. It is the latter that governs the dynamics and is linked to dynamic heterogeneity. This questions the direct role of the local icosahedral ordering in glassy slow dynamics and suggests that the growing length scale of structural order is essential for the slowing down of dynamics and the non-local cooperativity in particle motion.