Institute for Computational Physics, University of Stuttgart, Stuttgart, Germany.
J Chem Phys. 2011 Aug 7;135(5):054514. doi: 10.1063/1.3623783.
We report on a computer simulation study of a Lennard-Jones liquid confined in a narrow slit pore with tunable attractive walls. In order to investigate how freezing in this system occurs, we perform an analysis using different order parameters. Although some of the parameters indicate that the system goes through a hexatic phase, other parameters do not. This shows that to be certain whether a system of a finite particle number has a hexatic phase, one needs to study not only a large system, but also several order parameters to check all necessary properties. We find that the Binder cumulant is the most reliable one to prove the existence of a hexatic phase. We observe an intermediate hexatic phase only in a monolayer of particles confined such that the fluctuations in the positions perpendicular to the walls are less than 0.15 particle diameters, i.e., if the system is practically perfectly 2D.
我们报告了一项关于朗纳德-琼斯液体在可调谐吸引壁的窄缝孔中受限的计算机模拟研究。为了研究该系统中的冻结是如何发生的，我们使用不同的序参数进行了分析。尽管有些参数表明系统经历了六方相，但其他参数则没有。这表明，要确定有限粒子数的系统是否具有六方相，不仅需要研究大系统，还需要研究几个序参数以检查所有必要的性质。我们发现，Binder 累积量是证明六方相存在的最可靠方法。我们仅在单层粒子受限的情况下观察到中间六方相，使得垂直于壁的位置的波动小于 0.15 个粒子直径，即，如果系统实际上是完全二维的。
