A critical evaluation of pressure scales at high temperatures by in situ X-ray diffraction measurements
A critical evaluation of pressure scales at high temperatures by in situ X-ray diffraction measurements
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DOI：
10.1016/j.pepi.2003.09.018
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发表时间：
2004-06-15
影响因子：
2.3
通讯作者：
Funakoshi, K
中科院分区：
文献类型：
--
作者：
Fei, YW;Li, J;Funakoshi, K
我们进行了多砧实验，同时在高压和高温下使用多种内部压力标准，包括安，铂，氧化镁，钨，钼，钯，和银。在压力高达28 GPa和温度在300和2173 K之间收集了An，Pt和MgO的大量同步辐射X射线衍射数据。我们比较了从不同的压力尺度计算的压力，并证明了使用不同的压力标准或相同标准的不同热状态方程的压力测定存在很大的差异。这种比较使我们能够定量地确定在高P-T实验中使用不同压力标度的压力差异。使用MgO标度[J. Geophys. Res. 106（2001）515]作为参考压力标度，提出了与MgO标度一致的新的Au和Pt标度。我们进一步研究了常数q值（Mie-Gruneisen关系中Gruneisen参数的体积依赖性）假设的有效性，并表明q作为温度和压力的函数的表达式可能是必要的，以最好地拟合同时高P-T数据。(C)2004 Elsevier B. V.保留所有权利。
We conducted multi-anvil experiments at simultaneous high pressures and temperatures using multiple internal pressure standards including An, Pt, MgO, W, Mo, Pd, and Ag. Extensive synchrotron X-ray diffraction data for An, Pt, and MgO were collected at pressures up to 28 GPa and temperatures between 300 and 2173 K. We compare pressures calculated from different pressure scales and demonstrate large discrepancies in pressure determination using different pressure standards or different thermal equations of state for the same standard. The comparison allows us to quantitatively determine the differences in pressure using different pressure scales in the high P-T experiments. Using the MgO scale of [J. Geophys. Res. 106 (2001) 515] as a reference pressure scale, new Au and Pt scales are presented that are consistent with the MgO scale. We further examined the validity of the assumption of constant q value (volume dependence of the Gruneisen parameter in the Mie-Gruneisen relation) for the calculations of thermal pressures, and show that an expression of q as a function of temperature and pressure may be necessary to best fit the simultaneous high P-T data. (C) 2004 Elsevier B.V. All rights reserved.