Superionic effect and anisotropic texture in Earth’s inner core driven by geomagnetic field

Sun，Shichuan1,2; He，Yu1,2,3; Yang，Junyi1,2; Lin，Yufeng4; Li，Jinfeng4; Kim，Duck Young3; Li，Heping1,2; Mao，Ho kwang3

2023-12-01

10.1038/s41467-023-37376-1

Nature Communications   Impact Factor & Quartile

2041-1723

Seismological observations suggest that Earth’s inner core (IC) is heterogeneous and anisotropic. Increasing seismological observations make the understanding of the mineralogy and mechanism for the complex IC texture extremely challenging, and the driving force for the anisotropic texture remains unclear. Under IC conditions, hydrogen becomes highly diffusive like liquid in the hexagonal-close-packed (hcp) solid Fe lattice, which is known as the superionic state. Here, we reveal that H-ion diffusion in superionic Fe-H alloy is anisotropic with the lowest barrier energy along the c-axis. In the presence of an external electric field, the alignment of the Fe-H lattice with the c-axis pointing to the field direction is energetically favorable. Due to this effect, Fe-H alloys are aligned with the c-axis parallel to the equatorial plane by the diffusion of the north–south dipole geomagnetic field into the inner core. The aligned texture driven by the geomagnetic field presents significant seismic anisotropy, which explains the anisotropic seismic velocities in the IC, suggesting a strong coupling between the IC structure and geomagnetic field.

SCI

English

NI Journal Papers

Others

Youth Innovation Promotion Association of the Chinese Academy of Sciences[2020394];National Natural Science Foundation of China-Yunnan Joint Fund[42074104];

Science & Technology - Other Topics

Multidisciplinary Sciences

WOS:000959887700012

NATURE PORTFOLIO

2-s2.0-85150963626

Scopus

1.Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang,Guizhou,550081,China
2.University of Chinese Academy of Sciences,Beijing,100049,China
3.Center for High Pressure Science and Technology Advanced Research,Shanghai,201203,China
4.Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen,518055,China

Sun，Shichuan,He，Yu,Yang，Junyi,等. Superionic effect and anisotropic texture in Earth’s inner core driven by geomagnetic field[J]. Nature Communications,2023,14(1).

Sun，Shichuan.,He，Yu.,Yang，Junyi.,Lin，Yufeng.,Li，Jinfeng.,...&Mao，Ho kwang.(2023).Superionic effect and anisotropic texture in Earth’s inner core driven by geomagnetic field.Nature Communications,14(1).

Sun，Shichuan,et al."Superionic effect and anisotropic texture in Earth’s inner core driven by geomagnetic field".Nature Communications 14.1(2023).