The S pole distribution on magnetic grains in pyroxenite determined by magnetotactic bacteria

Minoru Funaki, Hideo Sakai, Tadashi Matsunaga, Shigehisa Hirose

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

North-seeking bacteria (NSB) with 1 μm diameters migrate to the S pole only. They were applied to identify the S pole determination on a polished surface of magnetite-rich pyroxenite whose natural remanent magnetization (NRM) intensity was 5.64 × 10-3 Am2 kg-1. The microscopic observations were performed under dark-field illumination in a controlled magnetic field to 10 μT. The NSB formed clusters on limited areas of magnetite grains and scattered over the whole magnetite grains. The NRM decreased to 1.02 × 10-5 Am2 kg-1 by alternating field (AF) demagnetization to 60 mT but no clusters appeared, while small populations of the NSB scattered on each grain. These scattered bacteria may gather toward the S pole resulting from magnetic domain walls. When the sample acquired saturation isothermal remanent magnetization (SIRM) to 1 T, the NSB formed dense clusters at the opposite side to the applied field direction on the many grains as expected. This evidence indicated that the NSB can be useful micro-organisms for the determination of fine magnetic structures. Some grains also had NSB clusters at the edge of the grains toward the field direction or did not exhibit any clusters. The complicated distribution of the clusters (the S poles) may be explained by shape anisotropy of the magnetic grains.

Original languageEnglish
Pages (from-to)253-260
Number of pages8
JournalPhysics of the Earth and Planetary Interiors
Volume70
Issue number3-4
DOIs
Publication statusPublished - 1992
Externally publishedYes

Fingerprint

pyroxenite
bacteria
poles
bacterium
magnetite
natural remanent magnetization
magnetization
slickenside
demagnetization
remanent magnetization
magnetic domains
distribution
organisms
domain wall
anisotropy
illumination
saturation
magnetic field
magnetic fields

ASJC Scopus subject areas

  • Geophysics
  • Space and Planetary Science
  • Physics and Astronomy (miscellaneous)
  • Astronomy and Astrophysics
  • Earth and Planetary Sciences(all)
  • Environmental Science(all)

Cite this

The S pole distribution on magnetic grains in pyroxenite determined by magnetotactic bacteria. / Funaki, Minoru; Sakai, Hideo; Matsunaga, Tadashi; Hirose, Shigehisa.

In: Physics of the Earth and Planetary Interiors, Vol. 70, No. 3-4, 1992, p. 253-260.

Research output: Contribution to journalArticle

Funaki, Minoru ; Sakai, Hideo ; Matsunaga, Tadashi ; Hirose, Shigehisa. / The S pole distribution on magnetic grains in pyroxenite determined by magnetotactic bacteria. In: Physics of the Earth and Planetary Interiors. 1992 ; Vol. 70, No. 3-4. pp. 253-260.
@article{b49d671e46ad44d0b55e3fd558fba36a,
title = "The S pole distribution on magnetic grains in pyroxenite determined by magnetotactic bacteria",
abstract = "North-seeking bacteria (NSB) with 1 μm diameters migrate to the S pole only. They were applied to identify the S pole determination on a polished surface of magnetite-rich pyroxenite whose natural remanent magnetization (NRM) intensity was 5.64 × 10-3 Am2 kg-1. The microscopic observations were performed under dark-field illumination in a controlled magnetic field to 10 μT. The NSB formed clusters on limited areas of magnetite grains and scattered over the whole magnetite grains. The NRM decreased to 1.02 × 10-5 Am2 kg-1 by alternating field (AF) demagnetization to 60 mT but no clusters appeared, while small populations of the NSB scattered on each grain. These scattered bacteria may gather toward the S pole resulting from magnetic domain walls. When the sample acquired saturation isothermal remanent magnetization (SIRM) to 1 T, the NSB formed dense clusters at the opposite side to the applied field direction on the many grains as expected. This evidence indicated that the NSB can be useful micro-organisms for the determination of fine magnetic structures. Some grains also had NSB clusters at the edge of the grains toward the field direction or did not exhibit any clusters. The complicated distribution of the clusters (the S poles) may be explained by shape anisotropy of the magnetic grains.",
author = "Minoru Funaki and Hideo Sakai and Tadashi Matsunaga and Shigehisa Hirose",
year = "1992",
doi = "10.1016/0031-9201(92)90192-X",
language = "English",
volume = "70",
pages = "253--260",
journal = "Physics of the Earth and Planetary Interiors",
issn = "0031-9201",
publisher = "Elsevier",
number = "3-4",

}

TY - JOUR

T1 - The S pole distribution on magnetic grains in pyroxenite determined by magnetotactic bacteria

AU - Funaki, Minoru

AU - Sakai, Hideo

AU - Matsunaga, Tadashi

AU - Hirose, Shigehisa

PY - 1992

Y1 - 1992

N2 - North-seeking bacteria (NSB) with 1 μm diameters migrate to the S pole only. They were applied to identify the S pole determination on a polished surface of magnetite-rich pyroxenite whose natural remanent magnetization (NRM) intensity was 5.64 × 10-3 Am2 kg-1. The microscopic observations were performed under dark-field illumination in a controlled magnetic field to 10 μT. The NSB formed clusters on limited areas of magnetite grains and scattered over the whole magnetite grains. The NRM decreased to 1.02 × 10-5 Am2 kg-1 by alternating field (AF) demagnetization to 60 mT but no clusters appeared, while small populations of the NSB scattered on each grain. These scattered bacteria may gather toward the S pole resulting from magnetic domain walls. When the sample acquired saturation isothermal remanent magnetization (SIRM) to 1 T, the NSB formed dense clusters at the opposite side to the applied field direction on the many grains as expected. This evidence indicated that the NSB can be useful micro-organisms for the determination of fine magnetic structures. Some grains also had NSB clusters at the edge of the grains toward the field direction or did not exhibit any clusters. The complicated distribution of the clusters (the S poles) may be explained by shape anisotropy of the magnetic grains.

AB - North-seeking bacteria (NSB) with 1 μm diameters migrate to the S pole only. They were applied to identify the S pole determination on a polished surface of magnetite-rich pyroxenite whose natural remanent magnetization (NRM) intensity was 5.64 × 10-3 Am2 kg-1. The microscopic observations were performed under dark-field illumination in a controlled magnetic field to 10 μT. The NSB formed clusters on limited areas of magnetite grains and scattered over the whole magnetite grains. The NRM decreased to 1.02 × 10-5 Am2 kg-1 by alternating field (AF) demagnetization to 60 mT but no clusters appeared, while small populations of the NSB scattered on each grain. These scattered bacteria may gather toward the S pole resulting from magnetic domain walls. When the sample acquired saturation isothermal remanent magnetization (SIRM) to 1 T, the NSB formed dense clusters at the opposite side to the applied field direction on the many grains as expected. This evidence indicated that the NSB can be useful micro-organisms for the determination of fine magnetic structures. Some grains also had NSB clusters at the edge of the grains toward the field direction or did not exhibit any clusters. The complicated distribution of the clusters (the S poles) may be explained by shape anisotropy of the magnetic grains.

UR - http://www.scopus.com/inward/record.url?scp=0026465320&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026465320&partnerID=8YFLogxK

U2 - 10.1016/0031-9201(92)90192-X

DO - 10.1016/0031-9201(92)90192-X

M3 - Article

AN - SCOPUS:0026465320

VL - 70

SP - 253

EP - 260

JO - Physics of the Earth and Planetary Interiors

JF - Physics of the Earth and Planetary Interiors

SN - 0031-9201

IS - 3-4

ER -