Density scaling in viscous liquids: from relaxation times to four-point susceptibilities.
Density scaling in viscous liquids: from relaxation times to four-point susceptibilities.
复制标题
粘性液体中的密度缩放：从弛豫时间到四点磁化率。
DOI：
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发表时间：
2009
影响因子：
4.4
通讯作者：
C. Roland
中科院分区：
文献类型：
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作者：
D. Coslovich;C. Roland
本文给出了Kob-Andersen-Lennard-Jones混合物四点动态磁化率chi（4）（t）随温度T和密度ρ的变化的数值计算。在T和rho的相关范围内，chi（4）（t）的完全t依赖性以及因此与动态相关体积成比例的chi（4）（t）中的最大值对于缩放变量rho（gamma）/T恒定的状态点是不变的。材料常数γ的值与叠加系统的弛豫时间τ与ρ（γ）/T的值相同。因此，动态相关体积是一个独特的功能，τ的任何热力学条件下的制度，密度标度举行。最后，我们研究的条件下，密度标度性质有关的压力和能量波动之间的强相关性的存在。
We present numerical calculations of a four-point dynamic susceptibility, chi(4)(t), for the Kob-Andersen Lennard-Jones mixture as a function of temperature T and density rho. Over a relevant range of T and rho, the full t-dependence of chi(4)(t) and thus the maximum in chi(4)(t), which is proportional to the dynamic correlation volume, are invariant for state points for which the scaling variable rho(gamma)/T is constant. The value of the material constant gamma is the same as that which superposes the relaxation time tau of the system versus rho(gamma)/T. Thus, the dynamic correlation volume is a unique function of tau for any thermodynamic condition in the regime where density scaling holds. Finally, we examine the conditions under which the density scaling properties are related to the existence of strong correlations between pressure and energy fluctuations.