Biphasic rate exchange in supercooled o -terphenyl from an ensemble analysis of single-molecule data
Biphasic rate exchange in supercooled o -terphenyl from an ensemble analysis of single-molecule data
复制标题
单分子数据集成分析中过冷邻三联苯的双相速率交换
DOI：
10.1103/physreve.98.040603
复制
发表时间：
2018
影响因子：
2.4
通讯作者：
Berg, Mark A.
中科院分区：
文献类型：
--
作者：
Kaur, Harveen;Verma, Sachin Dev;Paeng, Keewook;Kaufman, Laura J.;Berg, Mark A.
弛豫速率的不均匀性是过冷液体的一个重要特征。这意味着存在一个汇率交换过程来恢复遍历性，但这种交换的实验特征是不完整的，也是有争议的。在这里，最近提出的，合奏为基础的分析应用于单分子二色性数据提取详细的相关函数的旋转速率交换。一个大的晚期相位比探测器旋转慢1/4，是α弛豫时间的22倍，并且它有自己的汇率色散。一个小的早期阶段跟踪初始的旋转衰减。我们建议，晚期阶段是由于分子的相关速率的空间区域的核心和早期阶段是由于分子的边界。结果表明，在过冷液体中，初级弛豫过程涉及多个过程和多个空间场。
Heterogeneity in relaxation rates is a key feature of supercooled liquids. It implies the existence of a rate-exchange process to restore ergodicity, but the experimental characterization of that exchange has been incomplete and controversial. Here, a recently proposed, ensemble-based analysis is applied to single-molecule dichroism data to extract a detailed correlation function for rotational-rate exchange. A large, late phase istimes slower than the probe rotation and 22 times the alpha-relaxation time, and it has its own exchange-rate dispersion. A small, early phase tracks the initial rotational decay. We propose that the late phase is due to molecules in the core of spatial regions of correlated rates and that the early phase is due to molecules on the boundaries. The results imply that multiple processes and spatial fields are involved in the primary relaxation in supercooled liquids.