Equations of State and Phase Transformations in Rocky Materials to TPa Pressures

POSTER

Abstract

Recent advances in theory and technology have enabled constraining the equation of state (EOS) and phase transformation of materials to TPa pressures—conditions relevant to early Earth and large planets. This presentation summarizes our latest findings for a series of planetary materials listed below based on first-principles simulations and compared to laser-driven experiments when available:

(1) MgSiO3. Hugoniots of enstatite and bridgmanite calculated to 1.4 TPa, in addition to the Grüneisen parameter as a function of temperature and density.1

(2) SiO2. Mechanism of the bonded-to-atomic transition in liquid silica clarified and a new transition boundary rendered based on calculations and extensive analysis of thermodynamic, structural, and electronic properties.2

(3) MgO. The B1–B2 phase boundary benchmarked by quantum Monte Carlo calculations and accurate free-energy data (via thermodynamic integration) at T = 0 K up to the triple point.3

(4) Al2O3. Melting curves of the post-perovskite and U2S3 phases constrained to 1 TPa.4

The results necessitate reconsideration of predictions by planetary models that are based on empirical EOS models.

*This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0003856. Part of this work was performed under the auspices of U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Publication: 1. M. Millot et al., Geophys. Res. Lett. 47, e2019GL085476 (2020).
2. S. Zhang et al., J. Appl. Phys. 131, 071101 (2022).
3. S. Zhang et al., in preparation.
4. M. Ghosh et al., in preparation.

Presenters

  • Shuai Zhang

    • University of Rochester

Authors

  • Shuai Zhang

    • University of Rochester

  • Reetam Paul

    • University of Rochester

  • Maitrayee Ghosh

    • University of Rochester

  • Terry-Ann Suer

    • University of Rochester

  • Marius Millot

    • Lawrence Livermore Natl Lab

  • Miguel A Morales

    • Simons Foundation

  • Fionn D Malone

    • Lawrence Livermore Natl Lab

  • Raymond Jeanloz

    • University of California, Berkeley

  • Eva D Zurek

    • State Univ of NY - Buffalo

  • Suxing X Hu

    • Laboratory for Laser Energetics, University of Rochester

  • Ryan Rygg

    • University of Rochester

  • Gilbert W Collins

    • University of Rochester
    • Department of Mechanical Engineering, University of Rochester, Rochester, NY, USA. Laboratory for Laser Energetics, Rochester, NY, USA. Department of Physics and Astronomy,