中国物理B ›› 2025, Vol. 34 ›› Issue (3): 36102-036102.doi: 10.1088/1674-1056/ada759

所属专题： SPECIAL TOPIC — Structures and properties of materials under high pressure

• • 上一篇    下一篇

Structural and transport properties of (Mg,Fe)SiO3 at high temperature and high pressure

Shu Huang(黄澍)1, Zhiyang Xiang(向志洋)1, Shi He(何适)1,2, Luhan Yin(尹路寒)1, Shihe Zhang(张时赫)1,3, Chen Chen(陈晨)1, Kaihua He(何开华)1, and Cheng Lu(卢成)1,†   

  1. 1 School of Mathematics and Physics, China University of Geosciences (Wuhan), Wuhan 430074, China;
    2 Faculty of Materials Science and Chemistry, China University of Geosciences (Wuhan), Wuhan 430074, China;
    3 School of Future Technology, China University of Geosciences (Wuhan), Wuhan 430074, China
  • 收稿日期:2024-12-11 修回日期:2025-01-04 接受日期:2025-01-08 发布日期:2025-03-15
  • 通讯作者: Cheng Lu E-mail:lucheng@calypso.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12174352 and 12111530103) and the Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan) (Grant No. G1323523065).

Structural and transport properties of (Mg,Fe)SiO3 at high temperature and high pressure

Shu Huang(黄澍)1, Zhiyang Xiang(向志洋)1, Shi He(何适)1,2, Luhan Yin(尹路寒)1, Shihe Zhang(张时赫)1,3, Chen Chen(陈晨)1, Kaihua He(何开华)1, and Cheng Lu(卢成)1,†   

  1. 1 School of Mathematics and Physics, China University of Geosciences (Wuhan), Wuhan 430074, China;
    2 Faculty of Materials Science and Chemistry, China University of Geosciences (Wuhan), Wuhan 430074, China;
    3 School of Future Technology, China University of Geosciences (Wuhan), Wuhan 430074, China
  • Received:2024-12-11 Revised:2025-01-04 Accepted:2025-01-08 Published:2025-03-15
  • Contact: Cheng Lu E-mail:lucheng@calypso.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12174352 and 12111530103) and the Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan) (Grant No. G1323523065).

RichHTML

0

PDF (PC)

189

赞

摘要： (Mg,Fe)SiO$_3$ is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes. Here, we employ molecular dynamics simulations to investigate the structural and transport properties of (Mg,Fe)SiO$_3$ with varying iron contents at temperatures up to 5000 K and pressures up to 135 GPa. We thoroughly examine the effects of pressure, temperature, and iron content on the bond lengths, coordination numbers, viscosities, and electrical conductivities of (Mg,Fe)SiO$_3$. Our calculations indicate that the increase of pressure leads to the shortening of the O-O and Mg-O bond lengths, while the Si-O bond lengths exhibit the initial increase with pressure up to 40 GPa, after which they are almost unchanged. The coordination numbers of Si transition from four-fold to six-fold and eventually reach eight-fold coordination at 135 GPa. The enhanced pressure causes the decrease of the diffusion coefficients and the increase of the viscosities of (Mg,Fe)SiO$_3$. The increased temperatures slightly decrease the coordination numbers and viscosities, as well as obviously increase the diffusion coefficients and electrical conductivities of (Mg,Fe)SiO$_3$. Additionally, iron doping facilitates the diffusion of Si and O, reduces the viscosities, and enhances the electrical conductivities of (Mg,Fe)SiO$_3$. These findings advance fundamental understanding of the structural and transport properties of (Mg,Fe)SiO$_3$ under high temperature and high pressure, which provide novel insights for unraveling the complexities of geological processes within the Earth's mantle.

关键词: (Mg,Fe)SiO$_3$, structural and transport properties, molecular dynamics simulations, high temperature and high pressure

Abstract: (Mg,Fe)SiO$_3$ is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes. Here, we employ molecular dynamics simulations to investigate the structural and transport properties of (Mg,Fe)SiO$_3$ with varying iron contents at temperatures up to 5000 K and pressures up to 135 GPa. We thoroughly examine the effects of pressure, temperature, and iron content on the bond lengths, coordination numbers, viscosities, and electrical conductivities of (Mg,Fe)SiO$_3$. Our calculations indicate that the increase of pressure leads to the shortening of the O-O and Mg-O bond lengths, while the Si-O bond lengths exhibit the initial increase with pressure up to 40 GPa, after which they are almost unchanged. The coordination numbers of Si transition from four-fold to six-fold and eventually reach eight-fold coordination at 135 GPa. The enhanced pressure causes the decrease of the diffusion coefficients and the increase of the viscosities of (Mg,Fe)SiO$_3$. The increased temperatures slightly decrease the coordination numbers and viscosities, as well as obviously increase the diffusion coefficients and electrical conductivities of (Mg,Fe)SiO$_3$. Additionally, iron doping facilitates the diffusion of Si and O, reduces the viscosities, and enhances the electrical conductivities of (Mg,Fe)SiO$_3$. These findings advance fundamental understanding of the structural and transport properties of (Mg,Fe)SiO$_3$ under high temperature and high pressure, which provide novel insights for unraveling the complexities of geological processes within the Earth's mantle.

Key words: (Mg,Fe)SiO$_3$, structural and transport properties, molecular dynamics simulations, high temperature and high pressure

中图分类号:  (Computer simulation of liquid structure)

  • 61.20.Ja
61.50.Ks (Crystallographic aspects of phase transformations; pressure effects) 66.30.Pa (Diffusion in nanoscale solids) 66.20.Cy (Theory and modeling of viscosity and rheological properties, including computer simulation)