Constraints on the P-V-T equation of state of MgSiO3 perovskite
Constraints on the P-V-T equation of state of MgSiO3 perovskite
复制标题
MgSiO3钙钛矿P-V-T状态方程的约束
DOI：
10.2138/am-2000-2-314
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发表时间：
2000
影响因子：
3.1
通讯作者：
T. Duffy
中科院分区：
文献类型：
--
作者：
S. Shim;T. Duffy
摘要利用MgSiO_3钙钛矿的热弹性参数，通过对合成数据的反演，检验了状态方程对P、V、T实验数据的拟合。我们的结果表明，通过扩大的压力和温度范围，130 GPa和2500 K，格吕奈森参数，q（λ/λ lnV）的体积依赖性，可以解决到10%左右的最佳情况下。然而，模拟还显示了在MgSiO 3钙钛矿的弹性参数的当前可接受的不确定性内的体积模量KT 0和其压力导数K 'T0与q之间的强相关性。我们考虑了随机误差的影响，根据不同的测量技术的报告的不确定度。尽管激光加热金刚石砧座单元（LHDAC）技术具有显著更大的温度不确定性，但是扩展压力和温度范围的能力允许更高阶热力学参数的改进的分辨率。然而，LHDAC样品中温度不均匀性的系统误差可能导致q的高估。我们还对目前可用的数据集进行了Birch-Murhanghan-Debye（BMD）状态方程（EOS）拟合。与模拟结果一致，结合最近的LHDAC（Fiquet et al. 1998）和电阻加热金刚石压砧室（RHDAC）（Saxena et al. 1999）以及较低的P-T测量（Ross和哈岑1989; Wang et al. 1994; Utsumi et al. 1995; Funamori et al. 1996），我们得到q = 2.0（3）和γ0 = 1.42（4）。q = 2.0（3）和通常假设的q =1之间的差异强烈影响高阶热弹性参数的计算值[例如，a，（δ KT/δ T）P]以及一阶参数，如下地幔条件下的密度和体积模量。然而，可能的系统误差来源需要进一步研究，并且在较高P-T条件下的测量有望对MgSiO 3钙钛矿的热弹性参数产生更好的约束
Abstract Equation of state fits to experimental P,V,T data were examined by the inversion of synthetic data sets using the thermoelastic parameters of MgSiO3 perovskite. Our results show that by extending the pressure and temperature range to 130 GPa and 2500 K, the volume dependence of the Grüneisen parameter, q (∂lng/∂lnV), could be resolved to ~10% under the best circumstances. However, simulations also showed strong correlation between the bulk modulus, KT0, and its pressure derivative, K'T0, and q within the currently accepted uncertainty of elastic parameters for MgSiO3 perovskite. We considered the effect of random error based on the reported uncertainty for different measurement techniques. Even though the laser heated diamond-anvil cell (LHDAC) technique has significantly larger temperature uncertainty, the ability to extend the pressure and temperature ranges allows for improved resolution of higher order thermodynamic parameters. However, systematic error from temperature inhomogeneity in the LHDAC sample could result in overestimation of q. We also performed Birch-Murhanghan-Debye (BMD) equation of state (EOS) fits for currently available data sets. Consistent with the simulation results, combining recent LHDAC (Fiquet et al. 1998) and resistance heated diamond-anvil cell (RHDAC) (Saxena et al. 1999) with lower P-T measurements (Ross and Hazen 1989; Wang et al. 1994; Utsumi et al. 1995; Funamori et al. 1996) we obtained q = 2.0(3) and γ0 = 1.42(4). The difference between q = 2.0(3) and the normally assumed value of q =1 strongly affects calculated values for higher order thermoelastic parameters [e.g., a, (∂KT/∂T)P] as well as first order parameters, such as density and bulk modulus at lower mantle conditions. However, possible systematic error sources need to be further investigated and measurements at higher P-T conditions promise to yield better constraints on the thermoelastic parameters of MgSiO3 perovskite
影响因子：
1.4
作者：
N. Ross;R. Hazen
通讯作者：
N. Ross;R. Hazen