近年来,相分离动力学一直受到大家的关注,人们从技术和理论角度进行了研究.一个二元系统从混溶温度开始进行快速冷却,这个过程驱使两个相的形成和生长.这种自发生长过程遵从幂规律R(t)∝tn,R(t)是在t时刻的相分离域尺寸大小,增长指数n是一个重要的量,有效的反映了相分离域的增长机制.但是对于相分离液体的玻璃转变过程的研究相对较少.本文采用分子动力学(MD)模拟方法,提出了一个新的模型--相分离液体来研究玻璃转变过程.相分离在玻璃转变过程中,过冷液体分离为两个相.我们主要研究了体系的动力学不均匀性.发现两个相的动力学性质是不均匀的,两个相的玻璃转变温度是不一样的.分析得出,相分离液体在玻璃转变过程中存在着一个动力学奇异点.说明相分离可能是引起玻璃转变系统动力学奇异性的一个原因.
We propose a new model to study the glass transition of phase separation liquid using molecular dynamics simulations. Supercooled liquid separates into two phases during the glass transition. We focus on the dynamical heterogeneous properties of phase separation system. It is found that the dynamic properties of two phases are heterogeneous. The glass transition temperature of two phases is also different Further analysis shows that there exists a dynamic anomalous point in phase separation liquid. It suggests that phase separation may be one of the reasons that give rise to anomalous dynamics.
参考文献
| [1] | E. Velasco;S. Toxvaerd .Phase separation in two-dimensional binary fluids: A molecular dynamics study[J].Physical review.E.Statistical physics, plasmas, fluids, and related interdisciplinary topics,1996(1):605-610. |
| [2] | C. C. Hays;C. P. Kim;W. L. Johnson .Large supercooled liquid region and phase separation in the Zr-Ti-Ni-Cu-Be bulk metallic glasses[J].Applied physics letters,1999(8):1089-1091. |
| [3] | J.Z. Jiang;K. Saksl .Structural stability of Pd_(40)Cu_(30)Ni_(10)P_(20) metallic glass in supercooled liquid region[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2004(0):733-737. |
| [4] | E.S. Park;D.H. Kim .Phase separation and enhancement of plasticity in Cu-Zr-Al-Y bulk metallic glasses[J].Acta materialia,2006(10):2597-2604. |
| [5] | K. Vollmayr-Lee;W. Kob;K. Binder;A. Zippelius .Dynamical heterogeneities below the glass transition[J].The Journal of Chemical Physics,2002(12):5158-5166. |
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