[S-IT06] Interaction and Coevolution of the Core and Mantle

[SIT06-P14] Thermal conductivity of lower mantle minerals from ab initio anharmonic lattice dynamics

*出倉 春彦¹、土屋 卓久¹ (1.愛媛大学地球深部ダイナミクス研究センター)

キーワード：Earth's lower mantle, Phonon transport property, First-principles calculation

Determination of lattice thermal conductivity () of lower mantle minerals is a key to understanding the dynamics of the Earth’s interior. Although determination of κ was impractical in the deep Earth P, T condition for a long time, recent experimental and computational developments have been extending the accessible P and T ranges (e.g. H. Dekura, T. Tsuchiya and J. Tsuchiya, Phys. Rev. Lett. 110, 025904, 2013). Ab initio prediction of κ requires understanding of the phonon-phonon interaction associated with the lattice anharmonicity. We recently succeeded in developing an efficient method to calculate it based on the density-functional perturbation theory combined with anharmonic lattice dynamics theory, and applying to MgSiO₃ perovskite in the whole lower mantle P, T range for the first time. Next we extend our techniques to other lower mantle minerals such as MgSiO₃ post-perovskite, and now calculations of more realistic Fe-bearing systems are also started. In this presentation, we introduce the current situation of our research on κ.