Two-stage dissociation in MgSiO3 post-perovskite

Koichiro Umemoto; Renata M. Wentzcovitch

doi:10.1016/j.epsl.2011.09.032

Two-stage dissociation in MgSiO₃ post-perovskite

Koichiro Umemoto, Renata M. Wentzcovitch

Chemical Engineering and Materials Science

Research output: Contribution to journal › Article › peer-review

59 Scopus citations

Abstract

The fate of MgSiO₃ post-perovskite under TPa pressures is key information for understanding and modeling interiors of super-Earths-type exoplanets and solar giants' cores. Here, we report a dissociation of MgSiO₃ post-perovskite into CsCl-type MgO and P2₁/c-type MgSi₂O₅ at ~0.9TPa obtained by first principles calculations. P2₁/c-type MgSi₂O₅ should dissociate further into CsCl-type MgO and Fe₂P-type SiO₂ at ~2.1TPa. The first dissociation should occur in all solar giants and heavy super-Earths, while the second one should occur only in Jupiter and larger exoplanets. Both dissociations are endothermic and have large negative Clapeyron slopes. If the first dissociation should occur in the middle of a silicate mantle, it could promote mantle layering. We provide essential thermodynamic properties of P2₁/c-type MgSi₂O₅ for modeling interiors of super-Earths.

Original language	English (US)
Pages (from-to)	225-229
Number of pages	5
Journal	Earth and Planetary Science Letters
Volume	311
Issue number	3-4
DOIs	https://doi.org/10.1016/j.epsl.2011.09.032
State	Published - Nov 15 2011

Bibliographical note

Funding Information:
We would like to thank Professor D. A. Yuen for fruitful discussions. Calculations have been done using the Quantum-ESPRESSO package ( Giannozzi et al., 2009 ) and VLab software ( da Silveira et al., 2008 ). Research was supported by NSF grants EAR-1047629 . Computations were performed at the Minnesota Supercomputing Institute and at the Laboratory for Computational Science and Engineering at the University of Minnesota.

Keywords

10 solar giants
First principles
Postperovskite
Pressure-induced phase transition
Super-Earth

Publisher link

10.1016/j.epsl.2011.09.032

Find It

Find It at U of M Libraries

Cite this

@article{cc7d1f4df13248f1982cd2d63d1b24f1,

title = "Two-stage dissociation in MgSiO3 post-perovskite",

abstract = "The fate of MgSiO3 post-perovskite under TPa pressures is key information for understanding and modeling interiors of super-Earths-type exoplanets and solar giants' cores. Here, we report a dissociation of MgSiO3 post-perovskite into CsCl-type MgO and P21/c-type MgSi2O5 at ~0.9TPa obtained by first principles calculations. P21/c-type MgSi2O5 should dissociate further into CsCl-type MgO and Fe2P-type SiO2 at ~2.1TPa. The first dissociation should occur in all solar giants and heavy super-Earths, while the second one should occur only in Jupiter and larger exoplanets. Both dissociations are endothermic and have large negative Clapeyron slopes. If the first dissociation should occur in the middle of a silicate mantle, it could promote mantle layering. We provide essential thermodynamic properties of P21/c-type MgSi2O5 for modeling interiors of super-Earths.",

keywords = "10 solar giants, First principles, Postperovskite, Pressure-induced phase transition, Super-Earth",

author = "Koichiro Umemoto and Wentzcovitch, {Renata M.}",

note = "Funding Information: We would like to thank Professor D. A. Yuen for fruitful discussions. Calculations have been done using the Quantum-ESPRESSO package ( Giannozzi et al., 2009 ) and VLab software ( da Silveira et al., 2008 ). Research was supported by NSF grants EAR-1047629 . Computations were performed at the Minnesota Supercomputing Institute and at the Laboratory for Computational Science and Engineering at the University of Minnesota. ",

year = "2011",

month = nov,

day = "15",

doi = "10.1016/j.epsl.2011.09.032",

language = "English (US)",

volume = "311",

pages = "225--229",

journal = "Earth and Planetary Science Letters",

issn = "0012-821X",

publisher = "Elsevier B.V.",

number = "3-4",

}

TY - JOUR

T1 - Two-stage dissociation in MgSiO3 post-perovskite

AU - Umemoto, Koichiro

AU - Wentzcovitch, Renata M.

N1 - Funding Information: We would like to thank Professor D. A. Yuen for fruitful discussions. Calculations have been done using the Quantum-ESPRESSO package ( Giannozzi et al., 2009 ) and VLab software ( da Silveira et al., 2008 ). Research was supported by NSF grants EAR-1047629 . Computations were performed at the Minnesota Supercomputing Institute and at the Laboratory for Computational Science and Engineering at the University of Minnesota.

PY - 2011/11/15

Y1 - 2011/11/15

N2 - The fate of MgSiO3 post-perovskite under TPa pressures is key information for understanding and modeling interiors of super-Earths-type exoplanets and solar giants' cores. Here, we report a dissociation of MgSiO3 post-perovskite into CsCl-type MgO and P21/c-type MgSi2O5 at ~0.9TPa obtained by first principles calculations. P21/c-type MgSi2O5 should dissociate further into CsCl-type MgO and Fe2P-type SiO2 at ~2.1TPa. The first dissociation should occur in all solar giants and heavy super-Earths, while the second one should occur only in Jupiter and larger exoplanets. Both dissociations are endothermic and have large negative Clapeyron slopes. If the first dissociation should occur in the middle of a silicate mantle, it could promote mantle layering. We provide essential thermodynamic properties of P21/c-type MgSi2O5 for modeling interiors of super-Earths.

AB - The fate of MgSiO3 post-perovskite under TPa pressures is key information for understanding and modeling interiors of super-Earths-type exoplanets and solar giants' cores. Here, we report a dissociation of MgSiO3 post-perovskite into CsCl-type MgO and P21/c-type MgSi2O5 at ~0.9TPa obtained by first principles calculations. P21/c-type MgSi2O5 should dissociate further into CsCl-type MgO and Fe2P-type SiO2 at ~2.1TPa. The first dissociation should occur in all solar giants and heavy super-Earths, while the second one should occur only in Jupiter and larger exoplanets. Both dissociations are endothermic and have large negative Clapeyron slopes. If the first dissociation should occur in the middle of a silicate mantle, it could promote mantle layering. We provide essential thermodynamic properties of P21/c-type MgSi2O5 for modeling interiors of super-Earths.

KW - 10 solar giants

KW - First principles

KW - Postperovskite

KW - Pressure-induced phase transition

KW - Super-Earth

UR - http://www.scopus.com/inward/record.url?scp=80054122813&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80054122813&partnerID=8YFLogxK

U2 - 10.1016/j.epsl.2011.09.032

DO - 10.1016/j.epsl.2011.09.032

M3 - Article

AN - SCOPUS:80054122813

SN - 0012-821X

VL - 311

SP - 225

EP - 229

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

IS - 3-4

ER -