Mokshin Anatolii V, Galimzyanov Bulat N
Kazan Federal University, 420000 Kazan, Russia.
J Chem Phys. 2015 Mar 14;142(10):104502. doi: 10.1063/1.4914172.
Due to high viscosity, glassy systems evolve slowly to the ordered state. Results of molecular dynamics simulation reveal that the structural ordering in glasses becomes observable over "experimental" (finite) time-scale for the range of phase diagram with high values of pressure. We show that the structural ordering in glasses at such conditions is initiated through the nucleation mechanism, and the mechanism spreads to the states at extremely deep levels of supercooling. We find that the scaled values of the nucleation time, τ1 (average waiting time of the first nucleus with the critical size), in glassy systems as a function of the reduced temperature, T˜, are collapsed onto a single line reproducible by the power-law dependence. This scaling is supported by the simulation results for the model glassy systems for a wide range of temperatures as well as by the experimental data for the stoichiometric glasses at the temperatures near the glass transition.
由于高粘度，玻璃态系统向有序状态的演化较为缓慢。分子动力学模拟结果表明，在具有高压力值的相图范围内，玻璃中的结构有序性在“实验”（有限）时间尺度上变得可观测。我们表明，在这种条件下玻璃中的结构有序性是通过成核机制启动的，并且该机制会扩展到过冷度极高的状态。我们发现，玻璃态系统中成核时间的标度值τ1（具有临界尺寸的第一个原子核的平均等待时间）作为约化温度T˜的函数，会塌缩到一条由幂律依赖关系可重现的单一曲线上。这种标度关系得到了广泛温度范围内模型玻璃态系统的模拟结果以及化学计量玻璃在玻璃转变温度附近的实验数据的支持。
