Arrested dynamics of the dipolar hard sphere model.
Arrested dynamics of the dipolar hard sphere model.
复制标题
偶极硬球模型的停滞动力学。
作者：
L. F. Elizondo;E. C. Cortés;P. F. Zubieta Rico;M. Medina;R. Castañeda;T. Voigtmann;G. Pérez
我们报告了分子动力学模拟和理论计算的综合结果，这些结果涉及代表偶极流体的模型系统中的各种动态停滞转变，即N（软核）刚性球体通过截断的偶极子-偶极子势相互作用。通过探索不同的浓度和温度，我们发现了平移和取向自由度动力学减慢的三种不同情况：在低（η = 0.2）和中（η = 0.4）体积分数下，两种动力学都是强耦合的，并在冷却时同时停止。在高浓度（η≥0.6）下，平移动力学表现出普通玻璃化转变的特征，无论是通过压缩还是冷却体系，但取向仍然是遍历的，因此表明存在部分阻滞态。在这种密度状态下，但在较低的温度下，取向动力学的松弛也会冻结。讨论了模拟的物理场景，并将其与自洽广义朗之万方程理论的结果进行了比较，两者都提供了对系统动态停滞转变的一致描述。我们的结果总结在一个截止态图中，它定性地组织了模拟数据，并提供了偶极流体的玻璃化转变的一般图像。
We report the combined results of molecular dynamics simulations and theoretical calculations concerning various dynamical arrest transitions in a model system representing a dipolar fluid, namely, N (soft core) rigid spheres interacting through a truncated dipole-dipole potential. By exploring different regimes of concentration and temperature, we find three distinct scenarios for the slowing down of the dynamics of the translational and orientational degrees of freedom: at low (η = 0.2) and intermediate (η = 0.4) volume fractions, both dynamics are strongly coupled and become simultaneously arrested upon cooling. At high concentrations (η ≥ 0.6), the translational dynamics shows the features of an ordinary glass transition, either by compressing or cooling down the system, but with the orientations remaining ergodic, thus indicating the existence of partially arrested states. In this density regime, but at lower temperatures, the relaxation of the orientational dynamics also freezes. The physical scenario provided by the simulations is discussed and compared against results obtained with the self-consistent generalized Langevin equation theory, and both provide a consistent description of the dynamical arrest transitions in the system. Our results are summarized in an arrested states diagram which qualitatively organizes the simulation data and provides a generic picture of the glass transitions of a dipolar fluid.
偶极胶体的可逆凝胶化和动力学停滞
DOI：
10.1209/0295-5075/78/26002
发表时间：
2007
期刊：
Europhysics Letters (EPL)
影响因子：
--
作者：
Blaak R
通讯作者：
Blaak R
磁胶体悬浮液的缩合、分层和定向排序
DOI：
10.1103/physreve.91.052127
发表时间：
2015
期刊：
Physical review. E, Statistical, nonlinear, and soft matter physics
影响因子：
--
作者：
S. M. Cattes;S. H. L. Klapp;M. Schoen
通讯作者：
M. Schoen