Direct visualization of the thermomagnetic behaviour of pseudo-single-domain magnetite particles
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
The study of the palaeomagnetic signal recorded by rocks allows scientists to understand the Earth’s past magnetic field and the formation of the geodynamo. The magnetic recording fidelity of this signal is dependent on the magnetic domain state it adopts. The most prevalent example found in nature is the pseudo-single-domain (PSD) structure, yet its recording fidelity is poorly understood. Here, the thermo-remanent behaviour of PSD magnetite (Fe3O4) particles, which dominate the magnetic signatures of many rock lithologies, is investigated using electron holography. This study provides spatially resolved magnetic information from individual Fe3O4 grains as a function of temperature, which has been previously inaccessible. A small exemplar Fe3O4 grain (~ 150 nm) exhibits dynamic movement of its magnetic vortex structure above 400˚C, recovering its original state upon cooling, whilst a larger exemplar Fe3O4 grain (~ 250 nm) is shown to retain its vortex state on heating to 550˚C, close to the Curie temperature of 580˚C. Hence, it is demonstrated that Fe3O4 grains containing vortex structures are indeed reliable recorders of palaeo-directional and -intensity information; and the presence of PSD magnetic signals does not preclude the successful recovery of palaeomagnetic signals.
Date Issued
2016-04-15
Date Acceptance
2016-03-23
ISSN
2375-2548
Publisher
American Association for the Advancement of Science
Start Page
1
End Page
5
Journal / Book Title
Science Advances
Volume
2
Issue
4
Copyright Statement
Copyright © 2016, The Authors
This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.
This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.
Sponsor
Natural Environment Research Council (NERC)
Identifier
https://advances.sciencemag.org/content/2/4/e1501801
Grant Number
NE/J020508/1
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
RECORDING FIDELITY
STABILITY
Palaeomagnetism
in situ transmission electron microscopy
magnetite
nanoparticles
off-axis electron holography
pseudo–single-domain states
thermo-remanent magnetisation
thermomagnetic behavior
Earth, Planet
Ferrosoferric Oxide
Magnetic Fields
Magnetics
Temperature
Temperature
Magnetics
Ferrosoferric Oxide
Magnetic Fields
Earth, Planet
Publication Status
Published
Article Number
e1501801
Date Publish Online
2016-04-15