Pulsed-field-remanence measurements on individual magnetotactic bacteria

We measured pulsed-magnetic-field remanences of individual cells of two types of magnetotactic bacteria. Wild-type magnetic vibrios displayed square remanence curves with the reversal field, H-rev reaching values up to 825 Oe (65.7 kA/m). We attribute the generally high values of H-rev to the elongated shape of the magnetosomes (length-to-width ratio, e approximate to 1.2) and to the comparatively short distances between the magnetosomes (8 nm). Cells of the rod-shaped Magnetobacterium bavaricum, on the other hand, which frequently contain more than 600 magnetosomes per cell, could gradually be demagnetised; the coercivity of remanence, H-cr of individual cells always ranged between 600 and 700 Oe (47.7-55.7 kA/m). The non-square remanence curves of M. bavaricum reflect a distribution of elongations and interactions between adjacent strands of magnetosomes within the braid-like chains.

@article{id117,
  author = {Hanzlik, M. and Winklhofer, M. and Petersen, N.},
  doi = {doi:10.1016/S0304-8853(02)00353-0},
  journal = {J. Magn. Magn. Mater.},
  language = {en},
  number = {2},
  pages = {258-267},
  title = {Pulsed-field-remanence measurements on individual magnetotactic bacteria},
  volume = {248},
  year = {2002},
}

%O Journal Article
%A Hanzlik, M.
%A Winklhofer, M.
%A Petersen, N.
%R doi:10.1016/S0304-8853(02)00353-0
%J J. Magn. Magn. Mater.
%G en
%N 2
%P 258-267
%T Pulsed-field-remanence measurements on individual magnetotactic bacteria
%V 248
%D 2002