Pabst Florian, Gabriel Jan Philipp, Böhmer Till, Weigl Peter, Helbling Andreas, Richter Timo, Zourchang Parvaneh, Walther Thomas, Blochowicz Thomas
Institute of Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany.
Institute of Applied Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany.
J Phys Chem Lett. 2021 Apr 15;12(14):3685-3690. doi: 10.1021/acs.jpclett.1c00753. Epub 2021 Apr 8.
One of the unsolved problems of dynamics in supercooled liquids are the differences in spectral shape of the structural relaxation observed among different methods and substances, and a possible generic line shape has long been debated. We show that the light scattering spectra of very different systems, e.g., hydrogen bonding, van der Waals liquids, and ionic systems, almost perfectly superimpose and show a generic line shape of the structural relaxation, following ∝ ω at high frequencies. In dielectric spectra the generic behavior is recovered only for systems with low dipole moment, while in strongly dipolar liquids additional cross-correlation contributions mask the generic structural relaxation.
过冷液体动力学中尚未解决的问题之一是，在不同方法和物质中观察到的结构弛豫光谱形状存在差异，并且一种可能的通用线形长期以来一直存在争议。我们表明，非常不同的系统，例如氢键液体、范德华液体和离子系统的光散射光谱几乎完美地叠加在一起，并显示出结构弛豫的通用线形，在高频下遵循∝ω。在介电光谱中，只有对于偶极矩低的系统才能恢复通用行为，而在强偶极液体中，额外的交叉相关贡献掩盖了通用的结构弛豫。
