Phase behavior of density-dependent pair potentials.
Phase behavior of density-dependent pair potentials.
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DOI：
10.1063/1.2888977
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发表时间：
2008-03
期刊：
影响因子：
--
通讯作者：
Shiqi Zhou
中科院分区：
文献类型：
--
作者：
Shiqi Zhou
相图由最近提出的流体相的三阶热力学微扰理论(TPT)和最近提出的固体相的一阶热力学微扰理论(TPT)计算；潜在的粒间势由硬球斥力和具有吸引力的逆幂定律类型或Yukawa类型的微扰尾部组成，其范围随体积密度而变化。研究发现，除了与密度无关的势能相关的常见相变外，微扰尾部的密度依赖性还引起了一些新的相变，包括等结构的固-固相变和液-液相变。还展示了包括稳定流体(蒸气或液体)-面心立方(Fcc)-fcc和液-液-fcc，亚稳态液体中心(Bcc)-bcc的新型三点。研究还发现，相图敏感地依赖于密度依赖关系和基本势的具体数学形式。已公开的一些新的转变已经在复杂的流体和分子液体中实验观察到，而另一些仍有待实验验证。
Phase diagram is calculated by a recently proposed third-order thermodynamic perturbation theory (TPT) for fluid phase and a recently proposed first-order TPT for solid phases; the underlying interparticle potential consists of a hard sphere repulsion and a perturbation tail of an attractive inverse power law type or Yukawa type whose range varies with bulk densities. It is found that besides usual phase transitions associated with density-independent potentials, the density dependence of the perturbation tail evokes some additional novel phase transitions including isostructural solid-solid transition and liquid-liquid transition. Novel triple points are also exhibited which includes stable fluid (vapor or liquid)-face-centered cubic(fcc)-fcc and liquid-liquid-fcc, metastable liquid-body-centered cubic(bcc)-bcc. It also is found that the phase diagram sensitively depends on the density dependence and the concrete mathematical form of the underlying potentials. Some of the disclosed novel transitions has been observed experimentally in complex fluids and molecular liquids, while others still remain to be experimentally verified.