Structural and transport properties of(Mg,Fe)SiO_(3) at high temperature and high pressure  

作　　者：Shu Huang Zhiyang Xiang Shi He Luhan Yin Shihe Zhang Chen Chen Kaihua He Cheng Lu 黄澍;向志洋;何适;尹路寒;张时赫;陈晨;何开华;卢成

机构地区：[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

出　　处：《Chinese Physics B》2025年第3期123-129,共7页中国物理B(英文版)

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.12174352 and 12111530103);the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Grant No.G1323523065)。

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 

分 类 号：TG1[金属学及工艺—金属学]