2020/05/17 by Zhen Zhang, Dong‐Bo Zhang, Dong-Bo Zhang +5
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #Anharmonicity #Condensed matter physics #Geological and Geochemical Analysis #Geology #Geophysics #High-pressure geophysics and materials #Mantle (geology) #Materials science #Mineralogy #Phase Equilibria and Thermodynamics #Physics #Quasiparticle #Superconductivity #Thermodynamics #cond-mat.mtrl-sci #physics.geo-ph
paper · pdf · doi:10.1103/physrevb.104.184101
arxiv created 2020/05/17 · openalex publication_date 2021/11/04 · arxiv updated 2021/11/17 · openalex created_date 2021/11/22 · openalex updated_date 2026/08/06
Thermal conductivity (\ensuremathκ) of mantle minerals is key to understanding dynamics in the deep Earth. It controls the style of mantle convection and the timescale of cooling both the mantle and the core. Cubic CaSiO3 perovskite (CaPv) is the third most abundant mineral in the lower mantle (7\phantom\rule0.28em0exvol%). Despite its importance, no theoretical or experimental estimate of CaPv's \ensuremathκ is available. Theoretical investigations of its properties are challenging because of its strong anharmonicity. Experimental measurements at relevant pressures and temperatures are equally challenging. Here we present ab initio results for CaPv's \ensuremathκ obtained using the phonon quasiparticle approach to address its strong anharmonicity. We also offer experimental measurements of \ensuremathκ up to 67 GPa and 1950 K. Predictions and measurements are in good agreement and reveal a surprisingly large \ensuremathκ for cubic CaPv that can be explained on the basis of its high crystal structure symmetry. Despite its relatively low abundance, CaPv's \ensuremathκ increases the lower mantle \ensuremathκ by \ensuremath∼10%, if accounted for. \ensuremathκ of mantle regions enriched in subducted crustal materials will be more strongly impacted.