Critical single domain grain sizes in chains of interacting greigite particles: Implications for magnetosome crystals

Adrian R. Muxworthy, Wyn Williams, Andrew P. Roberts, Michael Winklhofer, Liao Chang, M. Pósfai

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Magnetotactic bacteria contain chains of magnetically interacting crystals (magnetosomes), which aid navigation (magnetotaxis). To improve the efficiency of magnetotaxis, magnetosome crystals (which can consist of magnetite or greigite) should be magnetically stable single domain (SD) particles. Larger particles subdivide into nonuniform multidomain (MD) magnetic structures that produce weaker magnetic signals, while small SD particles become magnetically unstable due to thermal fluctuations and exhibit superparamagnetic (SP) behavior. In this study, we determined the stable SD range as a function of grain elongation and interparticle separation for chains of identical greigite grains using fundamental parameters recently determined for greigite. Interactions significantly increase the stable SD range. For example, for cube-shaped greigite grains the upper stable SD threshold size is increased from 107 nm for isolated grains to 204 nm for touching grains arranged in chains. The larger critical SD grain size for greigite means that, compared to magnetite magnetosomes, greigite magnetosomes can produce larger magnetic signals without the need for intergrain interactions. Key Points Critical single-domain grain sizes for greigite determined Grain stability range for magnetotaxis calculated for greigite All observed greigite magnetosomes found to be single domain

Original languageEnglish
Pages (from-to)5430-5441
Number of pages12
JournalGeochemistry, Geophysics, Geosystems
Volume14
Issue number12
DOIs
Publication statusPublished - Dec 2013

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greigite
grain size
crystal
Crystals
crystals
magnetic signals
Ferrosoferric Oxide
magnetite
navigation aids
navigation aid
particle
Magnetic structure
bacteria
elongation
critical point
Elongation
Bacteria
Navigation
interactions
thresholds

Keywords

  • greigite
  • magnetosome
  • single domain

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics

Cite this

Critical single domain grain sizes in chains of interacting greigite particles : Implications for magnetosome crystals. / Muxworthy, Adrian R.; Williams, Wyn; Roberts, Andrew P.; Winklhofer, Michael; Chang, Liao; Pósfai, M.

In: Geochemistry, Geophysics, Geosystems, Vol. 14, No. 12, 12.2013, p. 5430-5441.

Research output: Contribution to journalArticle

Muxworthy, Adrian R. ; Williams, Wyn ; Roberts, Andrew P. ; Winklhofer, Michael ; Chang, Liao ; Pósfai, M. / Critical single domain grain sizes in chains of interacting greigite particles : Implications for magnetosome crystals. In: Geochemistry, Geophysics, Geosystems. 2013 ; Vol. 14, No. 12. pp. 5430-5441.
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