Prediction of an U2S3-type polymorph of Al 2O3 at 3.7 Mbar

Koichiro Umemoto; Renata M Wentzcovitch

doi:10.1073/pnas.0711925105

Prediction of an U₂S₃-type polymorph of Al ₂O₃ at 3.7 Mbar

Koichiro Umemoto, Renata M Wentzcovitch

Chemical Engineering and Materials Science

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

56 Scopus citations

Abstract

We predict by first principles a phase transition in alumina at ≈3.7 Mbar and room temperature from the CaIrO₃-type polymorph to another with the U₂S₃-type structure. Because alumina is used as window material in shock-wave experiments, this transformation should be important for the analysis of shock data in this pressure range. Comparison of our results on all high-pressure phases of alumina with shock data suggests the presence of two phase transitions in shock experiments: the corundum to Rh ₂O₃(II)-type structure and the Rh₂O ₃(II)-type to CaIrO₃-type structure. The transformation to the U₂S₃-type polymorph is in the pressure range reached in the mantle of recently discovered terrestrial exoplanets and suggests that the multi-megabar crystal chemistry of planetforming minerals might be related to that of the rare-earth sulfides.

Original language	English (US)
Pages (from-to)	6526-6530
Number of pages	5
Journal	Proceedings of the National Academy of Sciences of the United States of America
Volume	105
Issue number	18
DOIs	https://doi.org/10.1073/pnas.0711925105
State	Published - May 6 2008

Keywords

Alumina
First-principles calculation
High-pressure phase transition
Postperovskite
Rare-earth sulfide structure

Publisher link

10.1073/pnas.0711925105

Find It

Find It at U of M Libraries

Cite this

@article{b0c499361dae4aa481654478f5a357e4,

title = "Prediction of an U2S3-type polymorph of Al 2O3 at 3.7 Mbar",

abstract = "We predict by first principles a phase transition in alumina at ≈3.7 Mbar and room temperature from the CaIrO3-type polymorph to another with the U2S3-type structure. Because alumina is used as window material in shock-wave experiments, this transformation should be important for the analysis of shock data in this pressure range. Comparison of our results on all high-pressure phases of alumina with shock data suggests the presence of two phase transitions in shock experiments: the corundum to Rh 2O3(II)-type structure and the Rh2O 3(II)-type to CaIrO3-type structure. The transformation to the U2S3-type polymorph is in the pressure range reached in the mantle of recently discovered terrestrial exoplanets and suggests that the multi-megabar crystal chemistry of planetforming minerals might be related to that of the rare-earth sulfides.",

keywords = "Alumina, First-principles calculation, High-pressure phase transition, Postperovskite, Rare-earth sulfide structure",

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

year = "2008",

month = may,

day = "6",

doi = "10.1073/pnas.0711925105",

language = "English (US)",

volume = "105",

pages = "6526--6530",

journal = "Proceedings of the National Academy of Sciences of the United States of America",

issn = "0027-8424",

publisher = "National Academy of Sciences",

number = "18",

}

TY - JOUR

T1 - Prediction of an U2S3-type polymorph of Al 2O3 at 3.7 Mbar

AU - Umemoto, Koichiro

AU - Wentzcovitch, Renata M

PY - 2008/5/6

Y1 - 2008/5/6

N2 - We predict by first principles a phase transition in alumina at ≈3.7 Mbar and room temperature from the CaIrO3-type polymorph to another with the U2S3-type structure. Because alumina is used as window material in shock-wave experiments, this transformation should be important for the analysis of shock data in this pressure range. Comparison of our results on all high-pressure phases of alumina with shock data suggests the presence of two phase transitions in shock experiments: the corundum to Rh 2O3(II)-type structure and the Rh2O 3(II)-type to CaIrO3-type structure. The transformation to the U2S3-type polymorph is in the pressure range reached in the mantle of recently discovered terrestrial exoplanets and suggests that the multi-megabar crystal chemistry of planetforming minerals might be related to that of the rare-earth sulfides.

AB - We predict by first principles a phase transition in alumina at ≈3.7 Mbar and room temperature from the CaIrO3-type polymorph to another with the U2S3-type structure. Because alumina is used as window material in shock-wave experiments, this transformation should be important for the analysis of shock data in this pressure range. Comparison of our results on all high-pressure phases of alumina with shock data suggests the presence of two phase transitions in shock experiments: the corundum to Rh 2O3(II)-type structure and the Rh2O 3(II)-type to CaIrO3-type structure. The transformation to the U2S3-type polymorph is in the pressure range reached in the mantle of recently discovered terrestrial exoplanets and suggests that the multi-megabar crystal chemistry of planetforming minerals might be related to that of the rare-earth sulfides.

KW - Alumina

KW - First-principles calculation

KW - High-pressure phase transition

KW - Postperovskite

KW - Rare-earth sulfide structure

UR - http://www.scopus.com/inward/record.url?scp=44449167563&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=44449167563&partnerID=8YFLogxK

U2 - 10.1073/pnas.0711925105

DO - 10.1073/pnas.0711925105

M3 - Article

C2 - 18451030

AN - SCOPUS:44449167563

SN - 0027-8424

VL - 105

SP - 6526

EP - 6530

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

IS - 18

ER -