Off-axis electron holography of magnetotactic bacteria: magnetic microstructure of strains MV-1 and MS-1
  • Metaadatok
Tartalom: http://dx.doi.org/10.1127/0935-1221/2001/0013-0671
Archívum: MTA Könyvtár
Gyűjtemény: Status = Published

Type = Article
Cím:
Off-axis electron holography of magnetotactic bacteria: magnetic microstructure of strains MV-1 and MS-1
Létrehozó:
Dunin-Borkowski, Rafael E.
McCartney, Martha R.
Pósfai, Mihály
Frankel, Richard B.
Bazylinski, Dennis A.
Buseck, Peter R.
Kiadó:
Schweizerbart und Borntraeger
Dátum:
2001-07-18
Téma:
QD06 Mineralogy / ásványtan
Tartalmi leírás:
Off-axis electron holography in the transmission electron microscope is used to characterize the magnetic microstructure of magnetotactic bacteria. The practical details of the technique are illustrated through
the examination of single cells of strains MV-1 and MS-1, which contain crystals of magnetite (Fe3O4) that are
~50 nm in size and are arranged in chains. Electron holography allows the magnetic domain structures within the
nanocrystals to be visualized directly at close to the nanometer scale. The crystals are shown to be single magnetic domains. The magnetization directions of small crystals that would be superparamagnetic if they were isolated are found to be constrained by magnetic interactions with adjacent, larger crystals in the chains. Magnetization reversal processes are followed in situ, allowing a coercive field of between 30 and 45mT to be measured for the MV-1 cell. To within experimental error, the remanent magnetizations of the chains are found to be equal to the saturation magnetization of magnetite (0.60T). A new approach is used to determine that the magnetic moments of the chains are 7 and 5×10-16Am2 for the 1600-nm long MV-1 and 1200-nm long MS-1 chains examined,
respectively. The degree to which the observed magnetic domain structure is reproducible between successive
measurements is also addressed.
Típus:
Article
NonPeerReviewed
Formátum:
application/pdf
Azonosító:
Dunin-Borkowski, Rafael E. and McCartney, Martha R. and Pósfai, Mihály and Frankel, Richard B. and Bazylinski, Dennis A. and Buseck, Peter R. (2001) Off-axis electron holography of magnetotactic bacteria: magnetic microstructure of strains MV-1 and MS-1. European Journal of Mineralogy, 13 (1). pp. 671-684. ISSN 0935-1221
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