Thermal Fluctuations in the Magnetic Ground State of the Molecular Cluster Mn{sub 12}O{sub 12} Acetate from {ital {mu}}SR and Proton NMR Relaxation

Journal Article · Thu Oct 01 04:00:00 EDT 1998 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.81.3773· OSTI ID:663749

Lascialfari, A; Borsa, F; Carretta, P ^[1]; Jang, Z H; Borsa, F ^[2]; Gatteschi, D ^[3]

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1. Dipartimento di Fisica A. Volta e Unita INFM di Pavia, Via Bassi 6, I27100 Pavia (Italy)
2. Department of Physics and Astronomy, Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States)
3. Department of Chemistry, University of Firenze, Via Maragliano 77, I50144 Firenze (Italy)

Measurements of the spin-lattice relaxation rate are reported for muons and protons as a function of temperature for different values of the applied magnetic field in the Mn{sub 12}O {sub 12} molecular cluster. Strongly field dependent maxima in the relaxation rate versus temperature are observed below 50thinspthinspK. The results are explained in terms of thermal fluctuations of the total magnetization of the cluster among the different orientations with respect to the anisotropy axis. The lifetimes of the different m components of the total spin, S{sub T}=10 , of the molecule are obtained from the experiment and shown to be consistent with the ones expected from a spin-phonon coupling mechanism. No clear evidence for macroscopic quantum tunneling was observed in the field dependence of the proton relaxation rate at low T . {copyright} {ital 1998} {ital The American Physical Society }

• Research Organization: Ames National Laboratory
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 663749
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 17 Vol. 81; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
FLUCTUATIONS
MANGANESE COMPOUNDS
MANGANESE OXIDES
MOLECULAR CLUSTERS
MUON PROBES
NMR SPECTRA
OXYGEN COMPOUNDS
SPIN-LATTICE RELAXATION