Shock compression of FeOOH and implications for iron-water interactions in super-earth magma oceans
Iron(Fe)-water reactions in a magma ocean can influence water storage and density of planets. These reactions can form Fe-O-H phases, whose density, melting, and electronic properties at planetary interior conditions are important for informing planetary models. Here, we study natural goethite (α-FeOOH) that is shock-compressed along its principal Hugoniot. Analysis of our velocity interferometer system for any reflector (VISAR) results extends the equation of state to over 800 GPa. X-ray diffraction and VISAR reflectivity results indicate the onset of melting occurs at ~95 GPa with complete melting by 166 GPa, which may be relevant to low seismic velocity anomalies observed above the core-mantle boundary. Analysis of X-ray emission spectroscopy results up to 285 GPa shows the spin crossover of Fe, with dominantly low spin Fe above ~265 GPa in the melt, supporting formation of dense basal magma oceans in terrestrial planets. Using our measured FeOOH densities, we model planetary interiors up to 10 Earth masses. Assuming FeOOH forms via iron-water reactions, the radius decreases by up to 28%, while the density increases by up to 165% compared to the unreacted case, providing an avenue to investigate water storage and evolution in super-Earths and sub-Neptunes.
Authors
- E. Boulard (ORCID: https://orcid.org/0000-0003-2865-6098)
- Nicholas Czapla
- Komal Bali (ORCID: https://orcid.org/0000-0003-4829-7141)
- A. Benuzzi‐Mounaix (ORCID: https://orcid.org/0000-0001-6248-9479)
- Caroline Dorn (ORCID: https://orcid.org/0000-0001-6110-4610)
- G. Morard (ORCID: https://orcid.org/0000-0002-4225-0767)
- Yanyao Zhang (ORCID: https://orcid.org/0000-0002-3846-1131)
- Lélia Libon (ORCID: https://orcid.org/0000-0001-5806-5796)
- Wendy L. Mao (ORCID: https://orcid.org/0000-0003-0595-7760)
- Eric Galtier (ORCID: https://orcid.org/0000-0002-0396-285X)
- A. L. Gleason
- S. Pandolfi
- Dimosthenis Sokaras (ORCID: https://orcid.org/0000-0001-8117-1933)
- Roberto Alonso‐Mori (ORCID: https://orcid.org/0000-0002-5357-0934)
- Huan Yang (ORCID: https://orcid.org/0000-0002-9965-3030)
- Xuehui Wei
- Qijun Che
- Alessandra Ravasio
- Amanda J. Chen
- Sang Heon Shim
- Hae Ja Lee
- Donghao Zheng
Institutions
- Centre National de la Recherche Scientifique (FR)
- Planetary Science Institute (US)
- École Polytechnique (FR)
- Princeton University (US)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- SLAC National Accelerator Laboratory (US)
- ETH Zurich (CH)
- Sorbonne Université (FR)
- Laboratoire pour l'Utilisation des Lasers Intenses (FR)
- Laboratoire de Minéralogie & Cosmochimie du Muséum (FR)
- Institut des Sciences de la Terre (FR)
- Institut de minéralogie, de physique des matériaux et de cosmochimie (FR)
- Université Gustave Eiffel (FR)
- Arizona State University (US)
- Université Grenoble Alpes (FR)
- Stanford University (US)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-12-27
- DOI
- https://doi.org/10.1038/s41467-025-67845-8
- Primary Topic
- High-pressure geophysics and materials
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- U.S. Department of Energy
- National Aeronautics and Space Administration
- Deutsche Forschungsgemeinschaft
- Agence Nationale de la Recherche
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Ministerio de Economía y Competitividad
- Nuclear Safety and Security Commission
- Centre National de la Recherche Scientifique
- Sichuan University
- Sorbonne Université
- Office of Science
- SLAC National Accelerator Laboratory