Skip directly to content

Viewing the inner Earth through a diamond window

NSF Award:

Constraints on core composition from nuclear resonant scattering and x-ray diffraction studies on Fe-light-element compounds  (University of Michigan Ann Arbor)

Experimental Investigations of Carbon in Earth's Core  (University of Michigan Ann Arbor)

Congressional Districts:
Research Areas:

Findings from NSF-supported high-pressure experiments suggest that the Earth's inner core may indeed be composed mostly of iron carbide (Fe7C3), a material thought to be abundant in the Earth's inner core.

During the experiments to investigate the high-pressure properties of Fe7C3, the researchers squeezed single crystals of Fe7C3 to megabar pressure in a diamond anvil cell and then probed the material with X-rays. As a result of magnetic transition, the Fe7C3 unexpectedly became more compressible at about half a megabar pressure, leading to a close match to the inner core density under relevant conditions. Such observations support the scenario of an inner core composed mainly of Fe7C3. They also suggest that the core is potentially the largest carbon reservoir on Earth.

Identifying the composition of the Earth's inner core could advance understanding of the planet's origin, composition and evolution, as well as physical and chemical properties.

The research was published in Geophysical Research Letters.


  • data suggests iron carbide may indeed be abundant in the earth's core
Studies suggest iron carbide may be abundant in the Earth's core.
Bin Chen and Jie Li, University of Michigan; Lili Gao, Esen Alp, and Jiyong Zhao, Argonne National Laboratory; Barbara Lavina and Przemyslaw Dera, University of Chicago

Recent Award Highlights

deep beneath the ocean floor, microbes attached to basalt produce iron sulfide (pyrite)

Life under an igneous rock in the deep blue sea

Thriving community of microbes discovered buried beneath the seafloor

Research Areas: Earth & Environment Locations: Massachusetts Michigan North Carolina
model of a lithium iron phosphate nanoparticle

Rethinking Battery Design

Model provides insights into improving rechargeable batteries

Research Areas: Earth & Environment, Chemistry & Materials, Nanoscience Locations: California Massachusetts Michigan