Thermal expansivity, bulk modulus, and melting curve of H2O–ice VII to 20 GPa
Thermal expansivity, bulk modulus, and melting curve of H2O–ice VII to 20 GPa
复制标题
H2O-ice VII 至 20 GPa 的热膨胀率、体积模量和熔化曲线
DOI：
--
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
R. Hemley
中科院分区：
文献类型：
--
作者：
Y. Fei;H. Mao;R. Hemley
在6 ~ 20 GPa和300-700 K的高温高压下，对冰VII和流体H_2O的状态方程性质进行了实验研究。该技术涉及使用同步加速器X射线衍射和外部加热的金刚石砧室直接测量固体的晶胞体积。在室温下冰VII的体积和体积模量的压力依赖性与以前的同步加速器X射线研究非常一致。的热膨胀率被确定为压力的函数，并适合一个新提出的唯象关系和Mie-Gruneisen状态方程的形式主义的结果。在一系列压力下通过X射线衍射直接测定冰VII的开始融化，发现与先前的体积测定结果雅阁。基于新数据进行热力学计算，以评估先前提出的静态和冲击波压缩的流体水状态方程的有效性范围。
Equation of state properties of ice VII and fluid H2O at high pressures and temperatures have been studied experimentally from 6 to 20 GPa and 300–700 K. The techniques involve direct measurements of the unit‐cell volume of the solid using synchrotron x‐ray diffraction with an externally heated diamond–anvil cell. The pressure dependencies of the volume and bulk modulus of ice VII at room temperature are in good agreement with previous synchrotron x‐ray studies. The thermal expansivity was determined as a function of pressure and the results fit to a newly proposed phenomenological relation and to a Mie–Gruneisen equation of state formalism. The onset of melting of ice VII was determined directly by x‐ray diffraction at a series of pressures and found to be in accord with previous volumetric determinations. Thermodynamic calculations based on the new data are performed to evaluate the range of validity of previously proposed equations of state for fluid water derived from static and shock‐wave compression...