Thermal conductivity of CaSiO3 perovskite at lower mantle conditions
Thermal conductivity of CaSiO3 perovskite at lower mantle conditions
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DOI：
10.1103/physrevb.104.184101
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发表时间：
2019-12
影响因子：
3.7
通讯作者：
Zhen Zhang;Dong-Bo Zhang;Kotaro Onga;Akira Hasegawa;K. Ohta;K. Hirose;R. Wentzcovitch
中科院分区：
文献类型：
--
作者：
Zhen Zhang;Dong-Bo Zhang;Kotaro Onga;Akira Hasegawa;K. Ohta;K. Hirose;R. Wentzcovitch
地幔矿物的热导率（$\kappa$）是地球动力学模拟中的一个基本性质。它控制着地幔对流的类型和地幔冷却和地核冷却的时间尺度。立方CaSiO_3钙钛矿（CaP_3）是下地幔（LM）中第三丰富的矿物（7体积%）。然而，尽管它的重要性，没有理论或实验估计CaPv的$\kappa$存在。由于其强非谐性，对其性质的理论研究具有挑战性。在相关高压和高温下的实验测量同样具有挑战性。在这里，我们提出了$ab$ $initio$CaPv的$\kappa$使用一个既定的声子准粒子的方法，可以解决其强非谐性获得的结果。我们还提供$\kappa$的实验测量。预测和测量是在良好的协议，并揭示了一个令人惊讶的大$\kappa$立方CaPv。尽管其相对较低的丰度，CaPv的$\kappa$可能会增加下地幔$\kappa$约10%，如果占。地壳物质富集的地幔区的$\kappa$将受到更强烈的影响。
Thermal conductivity ($\kappa$) of mantle minerals is a fundamental property in geodynamic modeling. It controls the style of mantle convection and the time scale of the mantle and core cooling. Cubic CaSiO$_3$ perovskite (CaPv) is the third most abundant mineral in the lower mantle (LM) (7 vol%). However, despite its importance, no theoretical or experimental estimate of CaPv's $\kappa$ exists. Theoretical investigations of its properties are challenging because of its strong anharmonicity. Experimental measurements at relevant high pressures and temperatures are equally challenging. Here we present $ab$ $initio$ results for CaPv's $\kappa$ obtained using an established phonon quasiparticle approach that can address its strong anharmonicity. We also offer experimental measurements of $\kappa$. Predictions and measurements are in good agreement and reveal a surprisingly large $\kappa$ for cubic CaPv. Despite its relatively low abundance, CaPv's $\kappa$ might increase the lower mantle $\kappa$ by approximately 10%, if accounted for. $\kappa$ of mantle regions enriched in crust material will be more strongly impacted.