The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics

, Volume 10, Issue 2, pp 259–263

Magnetisation of isolated single crystalline Fe-nanoparticles measured by a ballistic Hall micro-magnetometer

Authors

  • L. Theil Kuhn
    • Ørsted Laboratory, Niels Bohr Institute, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
  • A.K. Geim
    • Research Institute for Materials, University of Nijmegen, 6525 Nijmegen, The Netherlands
  • J.G.S. Lok
    • Research Institute for Materials, University of Nijmegen, 6525 Nijmegen, The Netherlands
  • P. Hedegård
    • Ørsted Laboratory, Niels Bohr Institute, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
  • K. Ylänen
    • Ørsted Laboratory, Niels Bohr Institute, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
  • J.B. Jensen
    • Ørsted Laboratory, Niels Bohr Institute, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
  • E. Johnson
    • Ørsted Laboratory, Niels Bohr Institute, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
  • P.E. Lindelof
    • Ørsted Laboratory, Niels Bohr Institute, Universitetsparken 5, 2100 Copenhagen Ø, Denmark

DOI: 10.1007/s100530050547

Cite this article as:
Theil Kuhn, L., Geim, A., Lok, J. et al. Eur. Phys. J. D (2000) 10: 259. doi:10.1007/s100530050547

Abstract:

We present here the first magnetisation measurements on isolated single crystalline Fe-nanoparticles performed with a ballistic Hall micro-magnetometer. The measurements have a sensitivity of \(\) and thus provide us the possibility to study the mechanisms of magnetisation reversal in a single nanoparticle. The magnetic properties of the nanoparticles are influenced by their crystal structure and shape, and the presence of an oxide surface layer. They exhibit curling of the magnetic moments, but also a novel hysteresis behaviour. The spin configurations found for the system agree well with numerical calculations based on a Heisenberg Hamiltonian including the exchange and dipole interaction and surface anisotropy.

PACS. 07.55.Jg Magnetometers for susceptibility, magnetic moment, and magnetization measurements - 36.40.Cg Electronic and magnetic properties of clusters - 61.46.+w Clusters, nanoparticles, and nanocrystalline materials

Copyright information

© EDP Sciences, Springer-Verlag, Società Italiana di Fisica 2000