Simultaneous high-pressure and high-temperature volume measurements of ice VII and its thermal equation of state
Simultaneous high-pressure and high-temperature volume measurements of ice VII and its thermal equation of state
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DOI：
10.1103/physrevb.82.134103
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发表时间：
2010-10
影响因子：
3.7
通讯作者：
E. Sugimura;T. Komabayashi;K. Hirose;N. Sata;Y. Ohishi;L. Dubrovinsky
中科院分区：
文献类型：
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作者：
E. Sugimura;T. Komabayashi;K. Hirose;N. Sata;Y. Ohishi;L. Dubrovinsky
我们进行了同时高压（cid：1）P（cid：2）和高温（cid：1）T（cid：2）晶胞体积（cid：1）V（cid：2）测量H2 O冰VII在外部加热的金刚石对顶砧单元使用原位同步X射线衍射技术与角色散系统。在P =33-50 GPa和T =873 K下收集冰VII的等温晶胞体积。在T =430-740 K和P =19-37 GPa下进行了非等温实验以进一步限制冰VII的P-V- T性质。使用参考温度下状态方程（cid：1）EoS（cid：2）的现有300 K压缩数据，从收集的高P-T数据构建冰VII的热EoS。冰VII的融化温度计算到P =40 GPa的热力学计算与新构建的EoS的冰VII。所得的融化温度高于先前的计算，因为新的EoS给出了较小的冰VII的摩尔体积。相反，计算的熔化曲线与最近的实验估计是一致的。
We conducted simultaneous high-pressure (cid:1) P (cid:2) and high-temperature (cid:1) T (cid:2) unit-cell volume (cid:1) V (cid:2) measurements of H 2 O ice VII in an externally heated diamond anvil cell using in situ synchrotron x-ray diffraction technique with an angle-dispersive system. Isothermal unit-cell volume of ice VII was collected at P =33–50 GPa with T =873 K. Nonisothermal experiments at T =430–740 K and P =19–37 GPa were also conducted to further constrain P - V - T properties of ice VII. Using the existing 300 K compression data for an equation of state (cid:1) EoS (cid:2) at the reference temperature, a thermal EoS of ice VII was constructed from the collected high-P - T data. The melting temperature of ice VII was computed up to P =40 GPa by thermodynamic calculations with the newly constructed EoS of ice VII. The resulting melting temperatures are higher than that of previous calculations since the new EoS gives a smaller molar volume of ice VII. In contrast, the calculated melting curves are consistent with recent experimental estimates.