Imperial College London
Portrait Picture

Professor Adrian Muxworthy

Faculty of Engineering, Department of Earth Science & Engineering

Professor of Earth and Planetary Magnetism
 
 
 
//

Contact

 

+44 (0)20 7594 6442adrian.muxworthy

 
 
//

Location

 

4.48Royal School of MinesSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Roberts:2017:10.1002/2017JB014860,
author = {Roberts, AP and Almeida, TP and Church, NS and Harrison, RJ and Heslop, D and Li, Y and Li, J and Muxworthy, AR and Williams, W and Zhao, X},
doi = {10.1002/2017JB014860},
journal = {Journal of Geophysical Research},
pages = {9534--9558},
title = {Resolving the origin of pseudo-single domain magnetic behavior},
url = {http://dx.doi.org/10.1002/2017JB014860},
volume = {122},
year = {2017}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The term “pseudo-single domain” (PSD) has been used to describe the transitional state in rockmagnetism that spans the particle size range between the single domain (SD) and multidomain (MD) states.The particle size range for the stable SD state in the most commonly occurring terrestrial magneticmineral, magnetite, is so narrow (~20–75 nm) that it is widely considered that much of the paleomagneticrecord of interest is carried by PSD rather than stable SD particles. The PSD concept has, thus, become thedominant explanation for the magnetization associated with a major fraction of particles that recordpaleomagnetic signals throughout geological time. In this paper, we argue that in contrast to the SD and MDstates, the term PSD does not describe the relevant physical processes, which have been documentedextensively using three-dimensional micromagnetic modeling and by parallel research in material scienceand solid-state physics. We also argue that features attributed to PSD behavior can be explained bynucleation of a single magnetic vortex immediately above the maximum stable SD transition size. Withincreasing particle size, multiple vortices, antivortices, and domain walls can nucleate, which producevariable cancellation of magnetic moments and a gradual transition into the MD state. Thus, while the termPSD describes a well-known transitional state, it fails to describe adequately the physics of the relevantprocesses. We recommend that use of this term should be discontinued in favor of “vortex state,” whichspans a range of behaviors associated with magnetic vortices.
AU  - Roberts,AP
AU  - Almeida,TP
AU  - Church,NS
AU  - Harrison,RJ
AU  - Heslop,D
AU  - Li,Y
AU  - Li,J
AU  - Muxworthy,AR
AU  - Williams,W
AU  - Zhao,X
DO  - 10.1002/2017JB014860
EP  - 9558
PY  - 2017///
SN  - 0148-0227
SP  - 9534
TI  - Resolving the origin of pseudo-single domain magnetic behavior
T2  - Journal of Geophysical Research
UR  - http://dx.doi.org/10.1002/2017JB014860
UR  - http://hdl.handle.net/10044/1/53732
VL  - 122
ER  -
Download