Neutron study of mesoscopic magnetic clusters: Mn{sub 12}O{sub 12}

Journal Article · Wed Oct 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.8819· OSTI ID:632631

Hennion, M ^[1]; Pardi, L ^[2]; Mirebeau, I ^[1]; Suard, E ^[3]; Sessoli, R; Caneschi, A ^[4]

---

1. Laboratoire Leon Brillouin (CEA-CNRS), CEA-Saclay, 91191 Gif-sur-Yvette (France)
2. National High Magnetic field Laboratory, Florida State University, 1800 E. Paul Dirac DR, Tallahassee, Florida 32306 (United States)
3. Institut Laue-Langevin, Boite Postale 156X, 38042 Grenoble Cedex (France)
4. Department of Chemistry, University of Florence, Via Maragliano 77, 50144 Firenze (Italy)

Neutron diffraction and inelastic neutron scattering in zero field have been performed on mesoscopic magnetic Mn{sub 12}O{sub 12} clusters, well known for their macroscopic quantum effects observed at low temperature. In addition to the static spin correlations of the cluster in its ground state, we have observed some energy levels related both to the anisotropy and to the exchange energies of the cluster, with their respective dynamical form factor. The temperature and Q dependences of the anisotropy energy levels can be qualitatively explained using a quantum model. Besides these expected modes, the most striking result is the observation of extended energy modes at energy values below those related to anisotropy. Their temperature and Q dependences differ from those expected for the energy levels of usual magnetic clusters. They indicate an additional spin coupling which must play a role in tunneling properties. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 632631
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 14 Vol. 56; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANISOTROPY
ENERGY LEVELS
INELASTIC SCATTERING
MAGNETIC MATERIALS
MANGANESE COMPOUNDS
MANGANESE OXIDES
MOLECULAR CLUSTERS
NEUTRON DIFFRACTION
RELAXATION
TUNNELING