PHASE-BEHAVIOR OF METASTABLE WATER
PHASE-BEHAVIOR OF METASTABLE WATER
复制标题
DOI：
10.1038/360324a0
复制
发表时间：
1992-11-26
期刊：
影响因子：
64.8
通讯作者：
STANLEY, HE
中科院分区：
文献类型：
--
作者：
POOLE, PH;SCIORTINO, F;STANLEY, HE
液态水相图的亚稳扩展表现出丰富的特征，这些特征在水的平衡性质中得到了体现。例如，4 ℃时的密度最大值和46 ℃时的等温压缩率最小值被认为反映了在过冷区域发生的热力学量行为中存在奇异性。“稳定性极限图解”3 -5表明，这些热力学异常现象源于机械稳定性的单一极限。（亚稳线），起源于液-气临界点，它决定了高温下过热和低温下过冷的极限。在这里，我们提出了一个全面的一系列的分子动力学模拟表明，相反，过冷异常是由一个新确定的临界点，在此之上的两个亚稳的非晶相的冰（以前被证明是分开的一阶transitions 6，7线）变得难以区分。这两种无定形冰相因此被纳入我们对液态的理解中，提供了水的亚稳态和稳定行为的更完整的图像。
THE metastable extension of the phase diagram of liquid water exhibits rich features that manifest themselves in the equilibrium properties of water. For example, the density maximum at 4-degrees-C and the minimum in the isothermal compressibility at 46-degrees-C are thought to reflect the presence of singularities in the behaviour of thermodynamic quantities occurring in the supercooled region The 'stability-limit conjecture'3-5 suggests that these thermodynamic anomalies arise from a single limit of mechanical stability (spinodal line), originating at the liquid-gas critical point, which determines the limit of both superheating at high temperatures and supercooling at low temperatures. Here we present a comprehensive series of molecular dynamics simulations which suggest that, instead, the supercooling anomalies are caused by a newly identified critical point, above which the two metastable amorphous phases of ice (previously shown to be separated by a line of first-order transitions6,7) become indistinguishable. The two amorphous ice phases are thus incorporated into our understanding of the liquid state, providing a more complete picture of the metastable and stable behaviour of water.