Journal article

Exchange constants and spin dynamics in Mn₁₂-acetate

  • Honecker, A. Institut für Theoretische Physik, Technische Universität Braunschweig, Germany
  • Fukushima, N. Institut für Theoretische Physik, Technische Universität Braunschweig, Germany - University of the Saarland, Theoretische Physik, Saarbrücken, Germany
  • Normand, Bruce Department of Physics, Fribourg University, Switzerland
  • Chaboussant, G. Laboratoire Léon Brillouin, CEA-SaclayGif-sur-Yvette, France
  • Güdel, Hans-Ulrich Departement für Chemie und Biochemie, Universität Bern, Switzerland
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    10.12.2004
Published in:
  • Journal of Magnetism and Magnetic Materials. - 2005, vol. 290-291, p. 966-969
English We have obtained new inelastic neutron scattering (INS) data for the molecular magnet Mn₁₂-acetate which exhibit at least six magnetic peaks in the energy range 5–35 meV. These are compared with a microscopic Heisenberg model for the 12 quantum spins localised on the Mn ions, coupled by four inequivalent magnetic exchange constants. A fit to the magnetic susceptibility under the constraint that the spin of the ground state be S=10 yields two dominant exchange constants of very similar value, J1≈J2≈65 K (≈5.5 meV), and two smaller exchange constants J3 and J4. We compute the low-lying excitations by exact numerical diagonalisation and demonstrate that the parameters determined from the ground state and susceptibility fit provide qualitative agreement with the excitations observed by INS.
Faculty
Faculté des sciences
Department
Physique
Language
  • English
Classification
Physics
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License undefined
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Persistent URL
https://folia.unifr.ch/unifr/documents/299773
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