skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: In-situ crystal structure determination of seifertite SiO 2 at 129 GPa: Studying a minor phase near Earth’s core–mantle boundary

Abstract

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.

Authors:
 [1];  [2];  [2];  [3];  [4];  [4];  [3]
  1. Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai (China)
  2. Carnegie Inst. of Science, Argonne, IL (United States). High Pressure Collaborative Access Team (HPCAT)
  3. Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai (China); Carnegie Inst. of Science, Washington, DC (United States). Geophysical Lab.
  4. 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)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES); National Natural Science Foundation of China (NNSFC); National Science Foundation (NSF)
OSTI Identifier:
1235471
Grant/Contract Number:  
NA0001974; FG02-99ER45775; AC02-06CH11357; 201402032; 41574080; U1530402; EAR-1345112; EAR-1447438
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
American Mineralogist
Additional Journal Information:
Journal Volume: 101; Journal Issue: 1; Journal ID: ISSN 0003-004X
Publisher:
Mineralogical Society of America
Country of Publication:
United States
Language:
ENGLISH
Subject:
58 GEOSCIENCES; High pressure; crystal structure; multigrain; SiO2; seifertite; synchrotron X-ray; deep mantle

Citation Formats

Zhang, Li, Popov, Dmitry, Meng, Yue, Wang, Junyue, Ji, Cheng, Li, Bing, and Mao, Ho-kwang. In-situ crystal structure determination of seifertite SiO 2 at 129 GPa: Studying a minor phase near Earth’s core–mantle boundary. United States: N. p., 2016. Web. doi:10.2138/am-2016-5525.
Zhang, Li, Popov, Dmitry, Meng, Yue, Wang, Junyue, Ji, Cheng, Li, Bing, & Mao, Ho-kwang. In-situ crystal structure determination of seifertite SiO 2 at 129 GPa: Studying a minor phase near Earth’s core–mantle boundary. United States. https://doi.org/10.2138/am-2016-5525
Zhang, Li, Popov, Dmitry, Meng, Yue, Wang, Junyue, Ji, Cheng, Li, Bing, and Mao, Ho-kwang. Fri . "In-situ crystal structure determination of seifertite SiO 2 at 129 GPa: Studying a minor phase near Earth’s core–mantle boundary". United States. https://doi.org/10.2138/am-2016-5525. https://www.osti.gov/servlets/purl/1235471.
@article{osti_1235471,
title = {In-situ crystal structure determination of seifertite SiO 2 at 129 GPa: Studying a minor phase near Earth’s core–mantle boundary},
author = {Zhang, Li and Popov, Dmitry and Meng, Yue and Wang, Junyue and Ji, Cheng and Li, Bing and Mao, Ho-kwang},
abstractNote = {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.},
doi = {10.2138/am-2016-5525},
url = {https://www.osti.gov/biblio/1235471}, journal = {American Mineralogist},
issn = {0003-004X},
number = 1,
volume = 101,
place = {United States},
year = {2016},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

Save / Share:

Works referencing / citing this record:

Ab Initio Molecular Dynamics Investigation of Molten Fe–Si–O in Earth's Core
journal, June 2019


High-pressure studies with x-rays using diamond anvil cells
journal, November 2016


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