Phase Relations of Iron Carbides Fe2C, Fe3C, and Fe7C3 at the Earth's Core Pressures and Temperatures

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Phase Relations of Iron Carbides Fe2C, Fe3C, and Fe7C3 at the Earth's Core Pressures and Temperatures. / Sagatov, N. E.; Gavryushkin, P. N.; Medrish, I. et al.

In: Russian Geology and Geophysics, Vol. 61, No. 12, 12.2020, p. 1345-1353.

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

BibTeX

@article{31f37807e2994eaf86a822da2a52168b,

title = "Phase Relations of Iron Carbides Fe2C, Fe3C, and Fe7C3 at the Earth's Core Pressures and Temperatures",

abstract = "Based on first-principle calculations in the framework of the density functional theory and structure prediction algorithms, we have determined iron carbide phases stable at the Earth{\textquoteright}s core pressures and temperatures. It is shown that Fe7C3 is unstable and de-composes into the mixture Fe2C + Fe3C over the entire range of pressures and temperatures specific to the Earth{\textquoteright}s inner core. Subsequent decomposition of Fe3C into the mixture Fe + Fe2C is unfavorable. We also predict a new low-temperature modification Fe3C-C2/m-II dynamically and thermodynamically stable over the pressure range 290–305 GPa.",

keywords = "iron carbides, USPEX, AIRSS, crystal structure prediction, quasi-harmonic approximation, CRYSTAL-STRUCTURE, STRUCTURE PREDICTION, C SYSTEM, CARBON, 1ST-PRINCIPLES, MORPHOLOGY, STABILITY, STATE, GPA",

author = "Sagatov, {N. E.} and Gavryushkin, {P. N.} and I. Medrish and Inerbaev, {T. M.} and Litasov, {K. D.}",

note = "Funding Information: The study was supported by the Russian Science Foundation, grant No. 17-17-01177. Publisher Copyright: {\textcopyright} 2020, V.S. Sobolev IGM, Siberian Branch of the RAS.",

year = "2020",

month = dec,

doi = "10.15372/RGG2019146",

language = "English",

volume = "61",

pages = "1345--1353",

journal = "Russian Geology and Geophysics",

issn = "1068-7971",

publisher = "Elsevier Science B.V.",

number = "12",

}

RIS

TY - JOUR

T1 - Phase Relations of Iron Carbides Fe2C, Fe3C, and Fe7C3 at the Earth's Core Pressures and Temperatures

AU - Sagatov, N. E.

AU - Gavryushkin, P. N.

AU - Medrish, I.

AU - Inerbaev, T. M.

AU - Litasov, K. D.

PY - 2020/12

Y1 - 2020/12

N2 - Based on first-principle calculations in the framework of the density functional theory and structure prediction algorithms, we have determined iron carbide phases stable at the Earth’s core pressures and temperatures. It is shown that Fe7C3 is unstable and de-composes into the mixture Fe2C + Fe3C over the entire range of pressures and temperatures specific to the Earth’s inner core. Subsequent decomposition of Fe3C into the mixture Fe + Fe2C is unfavorable. We also predict a new low-temperature modification Fe3C-C2/m-II dynamically and thermodynamically stable over the pressure range 290–305 GPa.

AB - Based on first-principle calculations in the framework of the density functional theory and structure prediction algorithms, we have determined iron carbide phases stable at the Earth’s core pressures and temperatures. It is shown that Fe7C3 is unstable and de-composes into the mixture Fe2C + Fe3C over the entire range of pressures and temperatures specific to the Earth’s inner core. Subsequent decomposition of Fe3C into the mixture Fe + Fe2C is unfavorable. We also predict a new low-temperature modification Fe3C-C2/m-II dynamically and thermodynamically stable over the pressure range 290–305 GPa.

KW - iron carbides

KW - USPEX

KW - AIRSS

KW - crystal structure prediction

KW - quasi-harmonic approximation

KW - CRYSTAL-STRUCTURE

KW - STRUCTURE PREDICTION

KW - C SYSTEM

KW - CARBON

KW - 1ST-PRINCIPLES

KW - MORPHOLOGY

KW - STABILITY

KW - STATE

KW - GPA

UR - http://www.scopus.com/inward/record.url?scp=85108610995&partnerID=8YFLogxK

U2 - 10.15372/RGG2019146

DO - 10.15372/RGG2019146

M3 - Article

VL - 61

SP - 1345

EP - 1353

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 12

ER -

ID: 27357391