Qin Hai-Rong, Lee Chun-Shing, Lü Yong-Jun
School of Physics, Beijing Institute of Technology, Beijing 100081, China.
Department of Applied Physics, Hong Kong Polytechnic University, Hong Kong, China.
Phys Rev E. 2023 Nov;108(5-2):055301. doi: 10.1103/PhysRevE.108.055301.
We propose a distinguishable-particle glassy model suitable for the molecular dynamics simulation of structural glasses. This model can sensitively tune the kinetic fragility of supercooled liquids in a wide range by simply changing the distribution of particle interactions. In the model liquid, we observe the occurrence of thermodynamic liquid-liquid phase transitions above glass transition. The phase transition is facilitated by lowering fragility. Prior to the liquid-liquid phase transition, our simulations verify the existence of a constant-volume heat capacity maximum varying with fragility. We reveal the characteristics of the equilibrium potential energy landscape in liquids with different fragility. Within the Gaussian excitation model, the liquid-liquid transition as well as the response to fragility is reasonably interpreted in configuration space.
我们提出了一种适用于结构玻璃分子动力学模拟的可区分粒子玻璃模型。该模型可通过简单改变粒子相互作用分布，在很宽范围内灵敏地调节过冷液体的动力学脆性。在模型液体中，我们观察到在玻璃化转变温度以上发生了热力学液 - 液相转变。降低脆性有利于该相变。在液 - 液相转变之前，我们的模拟证实了存在一个随脆性变化的等容热容量最大值。我们揭示了不同脆性液体中平衡势能面的特征。在高斯激发模型内，在构型空间中合理地解释了液 - 液相转变以及对脆性的响应。
