P‐V‐T relations of wadsleyite determined by in situ X‐ray diffraction in a large‐volume high‐pressure apparatus
P‐V‐T relations of wadsleyite determined by in situ X‐ray diffraction in a large‐volume high‐pressure apparatus
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DOI：
10.1029/2009gl038107
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发表时间：
2009-06
影响因子：
5.2
通讯作者：
T. Katsura;A. Shatskiy;M. Manthilake;S. Zhai;D. Yamazaki;Takuya Matsuzaki;T. Yoshino;A. Yoneda-
中科院分区：
文献类型：
--
作者：
T. Katsura;A. Shatskiy;M. Manthilake;S. Zhai;D. Yamazaki;Takuya Matsuzaki;T. Yoshino;A. Yoneda-
在11 ~ 20 GPa的压力和300 ~ 2100 K的温度下，通过多砧装置中的原位X射线衍射，精确测量了Mg 2SiO 4 wadsleyite的体积。固定等温体积模量KT 0 = 169.2GPa，得到其压力导数K′T0 = 4.1（1）。固定的德拜温度θ0 = 814 K给出了在环境压力下的Grüneisen参数γ0 = 1.64（2）和它的对数体积依赖性q = 1.5（1）。在常压下，等温体积模量、安德森-格吕奈森参数和热膨胀系数的压力导数分别为：（KT/T）P = −0.021（1）GPa/K，δT = 5.5（2），α0 = 2.31（3）× 10−5 + 1.18（3）× 10−8（T − 300）K−1。在地幔矿物中，硅镁石的热膨胀系数对压力和体积的依赖性最小。地幔过渡带上部的绝热温度梯度为0.34（1）K/km。
The volume of Mg2SiO4 wadsleyite has been precisely measured at pressures of 11 to 20 GPa and temperatures of 300 to 2100 K by means of in situ X‐ray diffraction in a multi‐anvil apparatus. The fixed isothermal bulk modulus KT0 = 169.2 GPa gives its pressure derivative K′T0 = 4.1(1). The fixed Debye temperature θ0 = 814 K gives a Grüneisen parameter at ambient pressure γ0 = 1.64(2) and its logarithmic volume dependence q = 1.5(1). The pressure derivative of the isothermal bulk modulus, Anderson‐Grüneisen parameter and thermal expansion coefficient at ambient pressure are found to be (∂KT/∂T)P = −0.021(1) GPa/K, δT = 5.5(2), α0 = 2.31(3) × 10−5 + 1.18(3) × 10−8 (T − 300) K−1. The pressure and volume dependence of thermal expansion coefficient of wadsleyite is the smallest among those of the mantle minerals. The adiabatic temperature gradient in the upper part of the mantle transition zone is 0.34(1) K/km.