Abstract
We report a detailed study of the effects that crystalline disorder has on the magnetic relaxation and quantum tunneling of benzoate clusters. Thanks to the absence of interstitial molecules in the crystal structure of this molecular compound, we have been able to isolate the influence of long-range crystalline disorder. For this, we compare results obtained under two extreme situations: a crystalline sample and a nearly amorphous material. The results show that crystalline disorder affects little the anisotropy, magnetic relaxation, and quantum tunneling of these materials. It follows that disorder is not a necessary ingredient for the existence of magnetic quantum tunneling. The results unveil, however, a subtle influence of crystallinity via the modification of the symmetry of dipole-dipole interactions. The faster tunneling rates measured for the amorphous material are accounted for by a narrower distribution of dipolar bias in this material, as compared with the crystalline sample.
2 More- Received 15 September 2009
DOI:https://doi.org/10.1103/PhysRevB.81.014427
©2010 American Physical Society
Synopsis
Appreciate the imperfections
Published 16 February 2010
Crystalline order is not a necessary condition for magnetic quantum tunneling in a molecular magnet.
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