Slow relaxation in a one-dimensional rational assembly of antiferromagnetically-coupled [Mn4] single-molecule-magnets

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dc.creatorLecren, L.
dc.creatorRoubeau, O.
dc.creatorCoulon, C.
dc.creatorLi, Yang-Guang
dc.creatorGoff, X. Le
dc.creatorWernsdorfer, W.
dc.creatorMiyasaka, H.
dc.creatorClerac, R.
dc.date2005-11-07
dc.date.accessioned2026-07-07T06:45:55Z
dc.date.available2026-07-07T06:45:55Z
dc.descriptionFour discrete MnIII/MnII tetra-nuclear complexes with double-cuboidal core were synthesized. dc magnetic measurements show that both Mn2+ - Mn3+ and Mn3+ - Mn3+ magnetic interactions are ferromagnetic in three samples leading to an S = 9 ground state for the Mn4 unit. Furthermore, these complexes are Single-Molecule Magnets (SMMs) clearly showing both thermally activated and ground state tunneling regimes. Slight changes in the [Mn4] core geometry result in an S = 1 ground state in fourth sample. A one-dimensional assembly of [Mn4] units was obtained in the same synthetic conditions with the subsequent addition of NaN3. Double chair-like N3- bridges connect identical [Mn4] units into a chain arrangement. This material behaves as an Ising assembly of S = 9 tetramers weakly antiferromagnetically coupled. Slow relaxation of the magnetization is observed at low temperature for the first time in an antiferromagnetic chain, following an activated behavior with 47 K and tau_0 = 7x10^-11 s. The observation of this original thermally activated relaxation process is induced by finite-size effects and in particular by the non-compensation of spins in segments of odd-number units. Generalizing the known theories on the dynamic properties of poly-disperse finite segments of antiferromagnetically coupled Ising spins, the theoretical expression of the characteristic energy gaps were estimated and successfully compared to the experimental values.
dc.description40 pages, 20 figures
dc.identifierhttps://arxiv.org/abs/cond-mat/0511170
dc.identifierhttp://arxiv.org/abs/cond-mat/0511170
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/103177
dc.subjectMesoscale and Nanoscale Physics
dc.subjectMaterials Science
dc.titleSlow relaxation in a one-dimensional rational assembly of antiferromagnetically-coupled [Mn4] single-molecule-magnets
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