The temperature-pressure-volume equation of state of γ-Mg2SiO4
The temperature-pressure-volume equation of state of γ-Mg2SiO4
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DOI：
10.2465/jmps.99.72
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发表时间：
2004-04
影响因子：
0.7
通讯作者：
M. Matsui;T. Katsura
中科院分区：
文献类型：
--
作者：
M. Matsui;T. Katsura
基于具有量子校正的呼吸壳模型MD模拟，我们计算了γ-Mg2SiO4的温度-压力-体积（T-P-V）状态方程（EOS），可用作温度高达2000 K和压力高达25 - 30 GPa的可靠压力校准标准。模拟使用先前为 Mg2SiO4 系统开发的经验离子间势来重现精确测量的结构和弹性特性。这些电势不仅适用于 γ-Mg2SiO4，也适用于较宽温度和压力范围内的 α-和 β-Mg2SiO4。我们通过使用最近报道的 MgO 和 γ-Mg2SiO4 同步 X 射线测量数据，评估了 γ-Mg2SiO4 的 T-P-V EOS 的准确性，该数据是在高温高压下在多砧装置中使用同步加速器辐射进行的。我们发现通过 Matsui 等人提出的 MgO EOS 估计压力。 (2000) 和 γ-Mg2SiO4 EOS 的结果非常吻合，两个 EOS 之间估计压力的平均差异小于 0.3 GPa，T 温度在 1500 到 2000 K 之间，P 温度在 19 到 23 GPa 之间。
Based on breathing-shell-model MD simulations with quantum correction, we calculated the temperature-pressure-volume (T-P-V) equation of state(EOS) of γ-Mg2SiO4 to be used as a reliable pressure calibration standard at temperatures up to 2000 K and pressures up to 25 - 30 GPa. The simulations use empirical interionic potentials, previously developed for the Mg2SiO4 system to reproduce accurately measured structural and elastic properties. The potentials are applicable not only to γ-Mg2SiO4, but also to α- and β-Mg2SiO4 over wide temperature and pressure ranges. We assessed the accuracy of the resulting T-P-V EOS of γ-Mg2SiO4, by using the recently reported data on simultaneous X-ray measurements of MgO and γ-Mg2SiO4, performed by using synchrotron radiation in a multi-anvil apparatus at high temperatures and pressures. We found that pressures estimated through the MgO EOS presented by Matsui et al. (2000) and those for the γ-Mg2SiO4 EOS agree very well, with the average differences in the estimated pressures between the two EOS’s less than 0.3 GPa at T between 1500 and 2000 K and P between 19 and 23 GPa.