Dudalov D E, Fomin Y D, Tsiok E N, Ryzhov V N
Institute for High Pressure Physics RAS, 142190 Kaluzhskoe shosse, 14, Troitsk, Moscow, Russia.
Soft Matter. 2014 Jul 21;10(27):4966-76. doi: 10.1039/c4sm00124a. Epub 2014 Jun 2.
We present a computer simulation study of the phase diagram and anomalous behavior of two-dimensional (2D) and three-dimensional (3D) classical particles repelling each other through an isotropic core-softened potential. As in the analogous three-dimensional case, in 2D a reentrant-melting transition occurs upon compression under not too high pressure, along with a spectrum of thermodynamic and dynamic anomalies in the fluid phase. However, in two dimensions the order of the region of anomalous diffusion and the region of structural anomaly is inverted in comparison with the 3D case, where there exists a water-like sequence of anomalies, and has a silica-like sequence. In the low density part of the 2D phase diagram, melting is a continuous two-stage transition, with an intermediate hexatic phase. All available evidence supports the Kosterlitz-Thouless-Halperin-Nelson-Young (KTHNY) scenario for this melting transition. On the other hand, at high density part of the phase diagram one first-order transition takes place.
我们展示了一项关于二维(2D)和三维(3D)经典粒子通过各向同性核软化势相互排斥的相图和反常行为的计算机模拟研究。与类似的三维情况一样,在二维中,在不太高的压力下压缩时会发生再入熔化转变,同时在流体相中出现一系列热力学和动力学反常现象。然而,与三维情况相比,二维中反常扩散区域和结构反常区域的顺序是相反的,三维中存在类似水的反常序列,而二维具有类似二氧化硅的序列。在二维相图的低密度部分,熔化是一个连续的两阶段转变,有一个中间六方相。所有现有证据都支持这种熔化转变的科斯特利茨 - Thouless - 哈珀林 - 尼尔森 - 杨(KTHNY)情景。另一方面,在相图的高密度部分发生一级转变。