Zero-field ^55Mn NMR studies of the Single-Molecule Magnet Mn12-Bromoacetate
Abstract
We report 55Mn NMR measurements on a single crystal of the single-molecule magnet (SMM) Mn12-Bromoacetate at temperatures from 1.4 to 3 K, below its blocking temperature of 3 K. The spectrum consists of 3 peaks attributed to the Mn4+ core and two inequivalent Mn3+ sites, confirming the magnetic structure of the Mn12 core and complementing EPR measurements. The second peak is split by quadrupolar interactions. T2 relaxation is fast and the spectrum becomes unobservable above about 3 K. T1 measurements on the first peak show Arrhenius behavior that indicates an energy gap of 14K, which yields a D value of 0.73K, as predicted based on data on similar SMM's. Planned studies of angular variation in applied fields should provide new clues to the mechanism of macroscopic quantum tunneling.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARB25006H