Nanomagnetic properties of the meteorite cloudy zone.
View / Open Files
Authors
Eggeman, Alexander S
Martineau, Benjamin
Saghi, Zineb
Blukis, Roberts
Bagot, Paul AJ
Publication Date
2018-12-04Journal Title
Proc Natl Acad Sci U S A
ISSN
0027-8424
Publisher
Proceedings of the National Academy of Sciences
Volume
115
Issue
49
Pages
E11436-E11445
Language
eng
Type
Article
Physical Medium
Print-Electronic
Metadata
Show full item recordCitation
Einsle, J., Eggeman, A. S., Martineau, B., Saghi, Z., Collins, S., Blukis, R., Bagot, P. A., et al. (2018). Nanomagnetic properties of the meteorite cloudy zone.. Proc Natl Acad Sci U S A, 115 (49), E11436-E11445. https://doi.org/10.1073/pnas.1809378115
Abstract
Meteorites contain a record of their thermal and magnetic history, written in the intergrowths of iron-rich and nickel-rich phases that formed during slow cooling. Of intense interest from a magnetic perspective is the "cloudy zone," a nanoscale intergrowth containing tetrataenite-a naturally occurring hard ferromagnetic mineral that has potential applications as a sustainable alternative to rare-earth permanent magnets. Here we use a combination of high-resolution electron diffraction, electron tomography, atom probe tomography (APT), and micromagnetic simulations to reveal the 3D architecture of the cloudy zone with subnanometer spatial resolution and model the mechanism of remanence acquisition during slow cooling on the meteorite parent body. Isolated islands of tetrataenite are embedded in a matrix of an ordered superstructure. The islands are arranged in clusters of three crystallographic variants, which control how magnetic information is encoded into the nanostructure. The cloudy zone acquires paleomagnetic remanence via a sequence of magnetic domain state transformations (vortex to two domain to single domain), driven by Fe-Ni ordering at 320 °C. Rather than remanence being recorded at different times at different positions throughout the cloudy zone, each subregion of the cloudy zone records a coherent snapshot of the magnetic field that was present at 320 °C. Only the coarse and intermediate regions of the cloudy zone are found to be suitable for paleomagnetic applications. The fine regions, on the other hand, have properties similar to those of rare-earth permanent magnets, providing potential routes to synthetic tetrataenite-based magnetic materials.
Sponsorship
European Research Council
Funder references
European Research Council (320750)
The Royal Society (uf130286)
European Research Council (291522)
Identifiers
External DOI: https://doi.org/10.1073/pnas.1809378115
This record's URL: https://www.repository.cam.ac.uk/handle/1810/286310
Rights
Licence:
http://www.rioxx.net/licenses/all-rights-reserved
Statistics
Total file downloads (since January 2020). For more information on metrics see the
IRUS guide.