Phase Diagram of H_2O: Thermodynamic Functions of the Phase Transitions of High-Pressure Ices

摘要

The analysis of the internal structure of the ice satellites of the Solar System's giant planets, Jupiter and Saturn, and the estimation of the composition of other water-containing cosmic bodies require thermodynamic information on the phase transformations in the water-ice system. This work presents experimental and theoretical data on the studies of the phase diagram of water (H_2O) and the thermodynamic properties of water ices that were generalized, analyzed, and systematized. A brief description of the equations of state for different modifications of high-pressure ices that are most frequently used in thermodynamic calculations is presented. Based on the mathematical treatment of available experimental data for phase equilibria in the water-ice system, the boundaries of the phase transitions between crystal ices I, II, III, V, VI, VII, VIII, and X and liquid water are constructed; in addition, the thermal dependences of the thermodynamic functions (changes in enthalpy, entropy, and volume) of most water-ice phase transitions are obtained.