Dynamic crossover in supercooled liquids induced by high pressure
Dynamic crossover in supercooled liquids induced by high pressure
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DOI：
10.1063/1.1564046
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发表时间：
2003-04-01
影响因子：
4.4
通讯作者：
Roland, CM
中科院分区：
文献类型：
--
作者：
Casalini, R;Paluch, M;Roland, CM
在玻璃化温度T-g附近的分子动力学的物理基础，包括凝聚态物质中未解决的主要问题之一。特别令人感兴趣的是，在比T-g高1.2倍的温度下观察到的弛豫特性的显著变化。在这里，我们描述的实验中，这些动态变化引起的压力变化。对于几种过冷液体，弛豫时间与动力学的变化被发现是不变的温度和压力。也就是说，分子运动的时间尺度决定了强分子间协同性的发生和伴随的动力学变化。虽然热力学变量，如温度和压力，影响动态交叉，控制变量是时间尺度。(C)2003年，美国物理学会。
The physics underlying the dynamics of molecules near their glass temperature, T-g, comprises one of the major unsolved problems in condensed matter. Of particular interest are the striking changes in relaxation properties observed at temperatures similar to1.2 times higher than T-g. Herein, we describe experiments in which these changes in dynamics are induced by pressure variations. For several supercooled liquids, the relaxation time associated with the change in dynamics is found to be invariant to both temperature and pressure. That is, the time scale of the molecular motions determines the onset of strong intermolecular cooperativity and the accompanying dynamical changes. While thermodynamic variables such as temperature and pressure influence the crossover in dynamics, the governing variable is the time scale. (C) 2003 American Institute of Physics.