| 초록 |
Particles in glass-forming liquids may form domains of locally favorable structures (LFS) upon supercooling. Whether and how the LFS domains would relate to the slow relaxation and heterogeneous dynamics of the glass-forming liquids have been issues of interest. According to the Stokes-Einstein relation and the Debye-Stokes-Einstein relation, the ratio of the translational (DT) and rotational (DR) diffusion coefficient should be a constant. In supercooled liquids and glasses, however, DT and DR decouple. In this study, we employ tracers and investigate the decoupling of the tracers. We find from our simulations that icosahedron (LFS in Wahnstrom liquids) tracers experience drastic decoupling upon cooling, on the other hand, DT and DR of bicapped square antiprism (LFS in KA liquids) tracers do not decouple significantly. The difference in the decoupling behavior between different types of tracers indicates that there should be the structural motif during in glasses. |
