High-pressure experimental study of tetragonal CaSiO3-perovskite to 200 GPa
High-pressure experimental study of tetragonal CaSiO3-perovskite to 200 GPa
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四方CaSiO3-钙钛矿200 GPa高压实验研究
DOI：
10.2138/am-2021-7913
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发表时间：
2021-12
影响因子：
3.1
通讯作者：
Zhu Mao
中科院分区：
文献类型：
--
作者：
Ningyu Sun;Hui Bian;Youyue Zhang;Jung-Fu Lin;Vitali B. Prakapenka;Zhu Mao
抽象的。在这项研究中，我们已经研究了晶体结构和状态方程的tetraxanthine CaSiO 3-钙钛矿高达200 GPa，使用同步辐射X射线衍射在激光加热的金刚石对顶砧细胞。淬火CaSiO 3-钙钛矿高于148 GPa的X射线衍射图清楚地表明，200，211，和220峰的立方相分裂成004+220，204+312，和224+400峰对，分别在tetraxide结构，和它们的计算的半高全宽（FWHM）表现出显着增加与压力。衍射峰的分布表明，在148和199 GPa之间，在300 K下，四元CaSiO 3-钙钛矿最有可能具有I4/mcm空间群，尽管可能仍然存在其他可能性。利用Birch-Murnaghan方程，我们确定了四元CaSiO_3-钙钛矿的状态方程，得到体积模量K_0T = 227（21）GPa，体积模量的压力导数K_0T ′ = 4.0（3）。使用我们的结果和文献值在580 K和50 GPa左右的模拟声速显示，四相和立方相之间的压缩波速度（VP）和剪切波速度（VS）的差异分别为5.3%和6.7%。在~110 GPa和1000 K时，这种相变导致VP和VS分别跳变4.3%和9.1%。由于Ti的加入可以提高转变温度，从四方相到立方相的转变可能具有与所观察到的冷俯冲板片周围的中-下地幔不连续性相一致的地震特征，这需要在未来的研究中进行探索。
Abstract. In this study, we have investigated the crystal structure and equation of state of tetragonal CaSiO3-perovskite up to 200 GPa using synchrotron X-ray diffraction in laser-heated diamond-anvil cells. X-ray diffraction patterns of the quenched CaSiO3-perovskite above 148 GPa clearly show that 200, 211, and 220 peaks of the cubic phase split into 004+220, 204+312, and 224+400 peak pairs, respectively, in the tetragonal structure, and their calculated full-width at half maximum (FWHM) exhibits a substantial increase with pressure. The distribution of diffraction peaks suggests that the tetragonal CaSiO3-perovskite most likely has an I4/mcm space group at 300 K between 148 and 199 GPa, although other possibilities might still exist. Using the Birch-Murnaghan equations, we have determined the equation of state of tetragonal CaSiO3-perovskite, yielding the bulk modulus K0T = 227(21) GPa with the pressure derivative of the bulk modulus, K0T′ = 4.0(3). Modeled sound velocities at 580 K and around 50 GPa using our results and literature values show the difference in the compressional (VP) and shear-wave velocity (VS) between the tetragonal and cubic phases to be 5.3 and 6.7%, respectively. At ~110 GPa and 1000 K, this phase transition leads to a 4.3 and 9.1% jump in VP and VS, respectively. Since the addition of Ti can elevate the transition temperature, the transition from the tetragonal to cubic phase may have a seismic signature compatible with the observed mid-lower mantle discontinuity around the cold subduction slabs, which needs to be explored in future studies.
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DOI：
10.1002/2013jb010905
发表时间：
2014-04
期刊：
Journal of Geophysical Research: Solid Earth
影响因子：
--
作者：
K. Kawai;T. Tsuchiya
通讯作者：
K. Kawai;T. Tsuchiya
影响因子：
5.2
作者：
S. Shim;R. Jeanloz;T. Duffy
通讯作者：
S. Shim;R. Jeanloz;T. Duffy
影响因子：
5.2
作者：
S. Akber‐Knutson;Mark S. T. Bukowinski;J. Matas
通讯作者：
S. Akber‐Knutson;Mark S. T. Bukowinski;J. Matas
影响因子：
3.7
作者：
L. Stixrude;C. Lithgow‐Bertelloni;B. Kiefer;P. Fumagalli
通讯作者：
L. Stixrude;C. Lithgow‐Bertelloni;B. Kiefer;P. Fumagalli
影响因子：
3.1
作者：
S. Ono;Y. Ohishi;K. Mibe
通讯作者：
S. Ono;Y. Ohishi;K. Mibe