地球内核超离子态铁合金及其效应  

Superionic Iron Alloys in Earth’s Inner Core and Their Effects

作　　者：何宇 孙士川 李和平[1] HE Yu;SUN Shichuan;LI Heping(Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,Guizhou,China)

机构地区：[1]中国科学院地球化学研究所,中国科学院地球内部物质高温高压重点实验室,贵州贵阳550081

出　　处：《高压物理学报》2024年第3期129-138,共10页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(42074104);中国科学院青年交叉团队项目(JCTD-2022-16)。

摘　　要：超离子态介于固态与液态之间,被认为广泛存在于地球和行星内部。计算研究发现,在地球内核温度压力条件下,铁-氢、铁-碳、铁-氧合金处于超离子态,表现为氢、碳、氧等元素在固态铁合金中像液体一样快速流动。流动的轻元素导致铁合金软化及地震波速降低,与地球物理观测到的内核密度亏损和低剪切波速的特征一致。内核超离子态铁-氢合金可以与地磁场发生相互作用,在偶极地磁场的驱动下形成定向排列组构,从而解释了内核的各向异性结构成因。内核超离子态铁-轻元素合金的发现更新了人们对内核物态的认知,对掌握地球内核的结构、组成和演化以及内核结构与地球磁场的关系等具有重要意义。Under the conditions of high temperature and high pressure,a series of materials transform into superionic states,which fall between the solid and liquid states and are widely believed to exist in the interior of Earth and exoplanets.Computational research has found that under the temperature and pressure of the Earth’s inner core,iron-hydrogen,iron-carbon,and iron-oxygen alloys transform to superionic states,manifested as elements such as hydrogen,carbon,and oxygen flowing rapidly like liquids in solid iron alloys.The flowing light elements cause softening of Fe alloys and a decrease in seismic wave velocities,explaining the characteristics of core density deficient and low shear wave velocity observed in geophysics.The superionic iron-hydrogen alloy in the core can interact with the geomagnetic field,forming a lattice preferred orientation fiber driven by a dipole geomagnetic field,explaining the origin of the anisotropic structure in the inner core.The discovery of superionic iron-light-element alloys in the inner core has updated our understanding of the state of the inner core,and is of great significance for understanding the structure,composition,and evolution of Earth’s inner core,as well as the relationship between the inner core structure and the Earth’s magnetic field.

关 键 词：超离子态 地球内核 铁合金 各向异性 第一性原理计算 

分 类 号：O521.2[理学—高压高温物理] P313[理学—物理]