Measurement and Modeling of Spin Dynamics in Mn_12-acetate
Abstract
We perform inelastic neutron scattering measurements on the molecular nanomagnet Mn_12-acetate. From a detailed characterization of the excitations up to 30meV, we isolate those of magnetic character and show that all of the low-energy modes are S = 9 excitations above the S = 10 ground state. We consider the most general model for the superexchange interaction parameters of the molecule, which is analyzed by exact diagonalization to obtain the energy spectrum and high-temperature series expansion to compute the susceptibility. Matching of theoretical results with experimental observation reveals strong constraints on possible parameter sets. We conclude that only a model with dominant exchange couplings J1 ∼ J2 ∼ 5.5meV is consistent with the experimental data.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARB25002C