Imperial College London
Portrait Picture

Professor Adrian Muxworthy

Faculty of Engineering, Department of Earth Science & Engineering

Professor of Earth and Planetary Magnetism
 
 
 
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Contact

 

+44 (0)20 7594 6442adrian.muxworthy

 
 
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Location

 

4.48Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Almeida:2016:10.1126/sciadv.1501801,
author = {Almeida, T and Muxworthy, AR and Kovacs, A and Williams, W and Brown, PD and Dunin-Borkowski, RE},
doi = {10.1126/sciadv.1501801},
journal = {Science Advances},
pages = {1--5},
title = {Direct visualization of the thermomagnetic behaviour of pseudo-single-domain magnetite particles},
url = {http://dx.doi.org/10.1126/sciadv.1501801},
volume = {2},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - 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 400C, recovering its original state upon cooling, whilst a larger exemplar Fe3O4 grain (~ 250 nm) is shown to retain its vortex state on heating to 550C, close to the Curie temperature of 580C. 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.
AU  - Almeida,T
AU  - Muxworthy,AR
AU  - Kovacs,A
AU  - Williams,W
AU  - Brown,PD
AU  - Dunin-Borkowski,RE
DO  - 10.1126/sciadv.1501801
EP  - 5
PY  - 2016///
SN  - 2375-2548
SP  - 1
TI  - Direct visualization of the thermomagnetic behaviour of pseudo-single-domain magnetite particles
T2  - Science Advances
UR  - http://dx.doi.org/10.1126/sciadv.1501801
UR  - https://advances.sciencemag.org/content/2/4/e1501801
UR  - http://hdl.handle.net/10044/1/32746
VL  - 2
ER  -
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