Lee Chun-Shing, Lulli Matteo, Zhang Ling-Han, Deng Hai-Yao, Lam Chi-Hang
Department of Applied Physics, Hong Kong Polytechnic University, Hong Kong, China.
Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
Phys Rev Lett. 2020 Dec 31;125(26):265703. doi: 10.1103/PhysRevLett.125.265703.
We perform kinetic Monte Carlo simulations of a distinguishable-particle lattice model of structural glasses with random particle interactions. By varying the interaction distribution and the average particle hopping energy barrier, we obtain an extraordinarily wide range of kinetic fragility. A stretching exponent, characterizing structural relaxation, is found to decrease with the kinetic fragility in agreement with experiments. The most fragile glasses are those exhibiting low hopping barriers and, more importantly, dramatic drops of entropies upon cooling toward the glass transition temperatures. The entropy drops reduce possible kinetic pathways and lead to dramatic slowdowns in the dynamics. In addition, the kinetic fragility is shown to correlate with a thermodynamic fragility.
我们对具有随机粒子相互作用的结构玻璃的可区分粒子晶格模型进行了动力学蒙特卡罗模拟。通过改变相互作用分布和平均粒子跳跃能垒，我们获得了范围极其广泛的动力学脆性。发现表征结构弛豫的拉伸指数随动力学脆性降低，这与实验结果一致。最脆弱的玻璃是那些具有低跳跃能垒的玻璃，更重要的是，在冷却至玻璃化转变温度时熵会急剧下降。熵的下降减少了可能的动力学途径，并导致动力学显著减慢。此外，动力学脆性与热力学脆性相关。
