In-situ crystal structure determination of seifertite SiO 2 at 129 GPa: Studying a minor phase near Earth’s core–mantle boundary
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai (China)
- Carnegie Inst. of Science, Argonne, IL (United States). High Pressure Collaborative Access Team (HPCAT)
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai (China); Carnegie Inst. of Science, Washington, DC (United States). Geophysical Lab.
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai (China); Carnegie Inst. of Science, Argonne, IL (United States). High Pressure Synergetic Consortium (HPSync)
Seifertite SiO₂ likely exists as a minor phase near the core–mantle boundary. By simulating the pressure and temperature conditions near the core–mantle boundary, seifertite was synthesized as a minor phase in a coarse-grained, polycrystalline sample coexisting with the (Mg,Fe)SiO₃ post-perovskite (pPv) phase at 129 GPa and 2500 K. Here we report the first in situ single-crystal structure determination and refinement of seifertite at high pressure and after a temperature quench from laser heating. We improved the data coverage of a minor phase from a diamond-anvil cell (DAC) by merging single-crystal data of seifertite from six selected grains that had different orientations. Observed systematic absences of reflections from the six individual grains allowed only one space group: Pbcn. The refined results of seifertite are in good agreement with the predictions from previous first-principles calculations at high pressure. This approach provides a method for structure determination of a minor phase in a mineral assemblage synthesized under P-T conditions representative of the deep Earth.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES); National Natural Science Foundation of China (NSFC); National Science Foundation (NSF)
- Grant/Contract Number:
- NA0001974; FG02-99ER45775; AC02-06CH11357; 201402032; 41574080; U1530402; EAR-1345112; EAR-1447438
- OSTI ID:
- 1235471
- Journal Information:
- American Mineralogist, Vol. 101, Issue 1; ISSN 0003-004X
- Publisher:
- Mineralogical Society of AmericaCopyright Statement
- Country of Publication:
- United States
- Language:
- ENGLISH
Web of Science
Ab Initio Molecular Dynamics Investigation of Molten Fe–Si–O in Earth's Core
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journal | June 2019 |
Contributed Review: Culet diameter and the achievable pressure of a diamond anvil cell: Implications for the upper pressure limit of a diamond anvil cell
|
journal | November 2018 |
High-pressure studies with x-rays using diamond anvil cells
|
journal | November 2016 |
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