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, University of Fribourg, 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 et de médecine
- Department
- Département de Physique
- Language
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- English
- Classification
- Physics
- License
- License undefined
- Identifiers
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- RERO DOC 4247
- DOI 10.1016/j.jmmm.2004.11.302
- Persistent URL
- https://folia.unifr.ch/unifr/documents/299773
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