Isothermal compressibility of supercooled water and evidence for a thermodynamic singularity at -45°C

R. J. Speedy, C. A. Angell

Research output: Contribution to journalArticle

704 Scopus citations

Abstract

Using a capillary technique for small samples, the isothermal compressibility KT of water has been measured to -26°C. Accelerating increases of KT at the lower temperatures can be described by an expression of the form KT = Aεγ [where ε = (T-TS)/TS], which is known to describe anomalies encountered in the vicinity of a thermodynamic singularity located at TS. The implication that the thermodynamic and certain other properties of water at lower temperatures may be decomposed into a normal component and an anomalous component which diverges at TS = -45°C is supported by analysis of numerous other thermodynamic and relaxation data which extend into the supercooled regime. The anomalous characteristics are shown to originate primarily in the sensitivity of the volume to temperature changes, suggesting a geometrical basis for the cooperative behavior. The singularity at TS = -45°C may be a lambda transition associated with the cooperative formation of an open hydrogen-bonded network, but the near coincidence of TS with the experimental homogeneous nucleation temperature suggests, as an alternative, that TS may correspond to the limit of mechanical stability for the supercooled liquid phase.

Original languageEnglish (US)
Pages (from-to)851-858
Number of pages8
JournalThe Journal of chemical physics
Volume65
Issue number3
DOIs
StatePublished - Jan 1 1976
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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