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Recreating Giants Impacts in the Laboratory: Shock Compression of MgSiO 3 Bridgmanite to 14 Mbar
Author(s) -
Millot Marius,
Zhang Shuai,
Fratanduono Dayne E.,
Coppari Federica,
Hamel Sebastien,
Militzer Burkhard,
Simonova Dariia,
Shcheka Svyatoslav,
Dubrovinskaia Natalia,
Dubrovinsky Leonid,
Eggert Jon H.
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl085476
Subject(s) - enstatite , shock (circulatory) , perovskite (structure) , materials science , silicate perovskite , equation of state , meteorite , compression (physics) , periclase , geology , mineralogy , geophysics , thermodynamics , physics , high pressure , astrobiology , chemistry , chondrite , magnesium , crystallography , medicine , metallurgy
Understanding giant impacts requires accurate description of how extreme pressures and temperatures affect the physical properties of the constituent materials. Here, we report shock experiments on two polymorphs of MgSiO3 : enstatite and bridgmanite (perovskite) crystals. We obtain pressure‐density shock equation of state to 14 Mbar and more than 9 g/cm3 , a 40% increase in density from previous data on MgSiO3 . Density‐functional‐theory molecular dynamics (DFT‐MD) simulations provide predictions for the shock Hugoniot curves for bridgmanite and enstatite and suggest that the Grüneisen parameter decreases with increasing density. The good agreement between the simulations and the experimental data, including for the shock temperature along the enstatite Hugoniot reveals that DFT‐MD simulations reproduce well the behavior of dense fluidMgSiO 3 . We also reveal a high optical reflectance indicative of a metal‐like electrical conductivity which supports the hypothesis that magma oceans may contribute to planetary magnetic field generation.