Visualized effect of oxidation on magnetic recording fidelity in pseudo-single-domain magnetite particles

Almeida, T. P. , Kasama, T., Muxworthy, A. R., Williams, W., Nagy, L., Hansen, T. W., Brown, P. D. and Dunin-Borkowski, R. E. (2014) Visualized effect of oxidation on magnetic recording fidelity in pseudo-single-domain magnetite particles. Nature Communications, 5, 5154. (doi: 10.1038/ncomms6154) (PMID:25300366) (PMCID:PMC4214405)

Abstract

Magnetite (​Fe3O4) is an important magnetic mineral to Earth scientists, as it carries the dominant magnetic signature in rocks, and the understanding of its magnetic recording fidelity provides a critical tool in the field of palaeomagnetism. However, reliable interpretation of the recording fidelity of ​Fe3O4 particles is greatly diminished over time by progressive oxidation to less magnetic iron oxides, such as maghemite (γ-Fe2O3), with consequent alteration of remanent magnetization potentially having important geological significance. Here we use the complementary techniques of environmental transmission electron microscopy and off-axis electron holography to induce and visualize the effects of oxidation on the magnetization of individual nanoscale ​Fe3O4 particles as they transform towards γ-Fe2O3. Magnetic induction maps demonstrate a change in both strength and direction of remanent magnetization within ​Fe3O4 particles in the size range dominant in rocks, confirming that oxidation can modify the original stored magnetic information.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Almeida, Dr Trevor
• Authors: Almeida, T. P., Kasama, T., Muxworthy, A. R., Williams, W., Nagy, L., Hansen, T. W., Brown, P. D., and Dunin-Borkowski, R. E.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Nature Communications
• Publisher: Nature Publishing Group
• ISSN: 2041-1723
• ISSN (Online): 2041-1723
• Copyright Holders: Copyright © 2014 Macmillan Publishers Limited
• First Published: First published in Nature Communications 5:5154
• Publisher Policy: Reproduced under a Creative Commons License