Compressibility Anomalies in Stretched Water and Their Interplay with Density Anomalies
Compressibility Anomalies in Stretched Water and Their Interplay with Density Anomalies
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DOI：
10.1021/acs.jpclett.7b02563
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发表时间：
2017-11-16
影响因子：
5.7
通讯作者：
Caupin, Frederic
中科院分区：
文献类型：
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作者：
Holten, Vincent;Qiu, Chen;Caupin, Frederic
水的许多性质与通常的液体相反，这一直困扰着科学家：例如，水在冷却时会膨胀，液态水的密度比冰大。为了解释这种反常行为，人们提出了几种理论，对过冷水（在冰稳定的条件下为液体）的性质有不同的预测。然而，区分这些理论与实验仍然是难以捉摸的，因为自发冰成核。在这里，我们测量了声速在液态水拉伸到负压，并推导出一个实验状态方程，它揭示了压缩性异常。我们显示了严格的热力学关系，这些异常是如何错综复杂地与密度异常。我们观察到的一些特征是两种水理论有效的必要条件。
Water keeps puzzling scientists because of its numerous properties which behave oppositely to those of usual liquids: for instance, water expands upon cooling, and liquid water is denser than ice. To explain this anomalous behavior, several theories have been proposed, with different predictions for the properties of supercooled water (liquid at conditions where ice is stable). However, discriminating between those theories with experiments has remained elusive because of spontaneous ice nucleation. Here we measure the sound velocity in liquid water stretched to negative pressure and derive an experimental equation of state, which reveals compressibility anomalies. We show by rigorous thermodynamic relations how these anomalies are intricately linked with the density anomaly. Some features we observe are necessary conditions for the validity of two theories of water.