Thermal expansion of Mg2SiO4 ringwoodite at high pressures
Thermal expansion of Mg2SiO4 ringwoodite at high pressures
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DOI：
10.1029/2004jb003094
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发表时间：
2004-12
影响因子：
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通讯作者：
T. Katsura;S. Yokoshi;Maoshuang Song;K. Kawabe;Tomoyuki Tsujimura;A. Kubo;E. Ito;Y. Tange;
中科院分区：
文献类型：
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作者：
T. Katsura;S. Yokoshi;Maoshuang Song;K. Kawabe;Tomoyuki Tsujimura;A. Kubo;E. Ito;Y. Tange;
[1]在温度为300 ~ 2000 K、压力为15 ~ 24 GPa和温度为300 K、压力为0 ~ 21 GPa的条件下测量了Mg 2SiO 4林伍德石的晶胞体积。使用配备有振荡系统的Kawai型多砧装置进行测量，以获得针对晶粒生长的高质量衍射图案。得到了Mg_2SiO_4林伍德石的压力-体积-温度关系式和参数。在0 GPa和300 K下，Mg 2SiO 4林伍德石的晶胞体积为524.8（1）A3（括号中的值为误差）。将等温体积模量固定为182 GPa，其压力导数为4.6（2）。在0 GPa下的热膨胀系数为α0 = 2.57（9）× 10−5 + 1.42（8）× 10−8（T − 300）K−1，其中T是绝对温度，单位为K，其对数体积依赖性，安德森-格吕尼森参数，为6.9（4）。等温体积弹性模量的温度导数为（KKT/KKT）= −0.029（1）GPa K−1。德拜温度θ为846（26）K。Gruneisen参数和它的对数体积依赖性分别为1.93（3）和3.5（3）。地幔中的绝热温度梯度在很大程度上取决于温度。在Mg 2SiO 4地幔模型中，当温度从1600 K增加到2000 K时，该值从0.29 K km-1增加到0.40 K km-1。
[1] Unit cell volumes of Mg2SiO4 ringwoodite were measured at temperatures from 300 to 2000 K and pressure from 15 to 24 GPa and at a temperature of 300 K and pressure from 0 to 21 GPa. The measurements were conducted using a Kawai-type multianvil apparatus that is equipped with an oscillation system to obtain high-quality diffraction pattern against grain growth. We obtained the following relations and parameters describing the pressure-volume-temperature relations of Mg2SiO4 ringwoodite. The unit cell volume of Mg2SiO4 ringwoodite at 0 GPa and 300 K is 524.8(1) A3 (values in parentheses are errors). Fixing the isothermal bulk modulus to 182 GPa, its pressure derivative is 4.6(2). The thermal expansion coefficient at 0 GPa is α0 = 2.57(9) × 10−5 + 1.42(8) × 10−8 (T − 300) K−1, where T is absolute temperature in K, and its logarithmic volume dependence, Anderson-Gruneisen parameter, is 6.9(4). The temperature derivative of the isothermal bulk modulus is (∂KT/∂T) = −0.029(1) GPa K−1. The Debye temperature, Θ, is 846(26) K. The Gruneisen parameter and its logarithmic volume dependence are 1.93(3) and 3.5(3), respectively. The adiabatic temperature gradient in the mantle largely depends on temperature. That in the model Mg2SiO4 mantle increases from 0.29 to 0.40 K km−1 when temperature increases from 1600 to 2000 K.