Field response of magnetic vortices in dusty olivine from the Semarkona chondrite

Nichols, C. I.O., Einsle, J. F. , Im, M.‐Y., Kasama, T., Saghi, Z., Midgley, P. A. and Harrison, R. J. (2019) Field response of magnetic vortices in dusty olivine from the Semarkona chondrite. Geochemistry, Geophysics, Geosystems, 20(3), pp. 1441-1453. (doi: 10.1029/2018GC008159)

Abstract

Recent paleomagnetic studies have constrained the strength and longevity of the magnetic field generated by the solar nebula, which has broad implications for the early evolution of the solar system. Paleomagnetic evidence was recorded by nanoscale iron inclusions in olivine crystals in the Semarkona LL 3.0 chondrite. These dusty olivines have been shown to be credible carriers of ancient magnetic remanence. The small scale of the iron inclusions presents several challenges for defining their fundamental magnetic properties. Here we present the first correlative study of the response of these magnetic structures under applied laboratory fields. Results show that the majority of particles are in a single‐vortex state and exhibit stable magnetic behavior in applied fields up to 200 mT. Experimental observations using Lorentz microscopy and magnetic transmission X‐ray microscopy are shown to compare well with the results of finite‐element micromagnetic simulations derived from 3‐D models of the particles obtained using electron tomography. This correlative approach may be used to characterize the fundamental magnetic behavior of many terrestrial and extraterrestrial paleomagnetic carriers in the single‐vortex to multivortex size range, which represent the vast majority of stable magnetic carriers in rocks and meteorites.

• Item Type: Articles
• Additional Information: The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007‐2013) ERC grant agreement 320750. Mi‐Young Im acknowledges support from DGIST R&D program of the Ministry of Science, ICT and Future Planning (18‐BT‐02). Work at ALS was supported by the U.S. Department of Energy under contract DE‐AC02‐05CH11231.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Einsle, Dr Joshua Franz
• Authors: Nichols, C. I.O., Einsle, J. F., Im, M.‐Y., Kasama, T., Saghi, Z., Midgley, P. A., and Harrison, R. J.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences > Earth Sciences
• Journal Name: Geochemistry, Geophysics, Geosystems
• Publisher: Wiley
• ISSN: 1525-2027
• ISSN (Online): 1525-2027
• Published Online: 12 February 2019
• Copyright Holders: Copyright © 2019 American Geophysical Union
• First Published: First published in Geochemistry, Geophysics, Geosystems 20(3):1441-1453
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher