We report the first example of a transition to long-range magnetic order in a purely dipolarly interacting molecular magnet. For the magnetic cluster compound Mn6O4Br4(Et2dbm)6, the anisotropy experienced by the total spin S=12 of each cluster is so small that spin-lattice relaxation remains fast down to the lowest temperatures, thus enabling dipolar order to occur within experimental times at Tc = 0.16 K. In high magnetic fields, the relaxation rate becomes drastically reduced and the interplay between nuclear- and electron-spin lattice relaxation is revealed.
@article{arxiv.cond-mat/0212372,
title = {Long-range ferromagnetic dipolar ordering of high-spin molecular clusters},
author = {A. Morello and F. L. Mettes and F. Luis and J. F. Fernandez and J. Krzystek and G. Aromi and G. Christou and L. J. de Jongh},
journal= {arXiv preprint arXiv:cond-mat/0212372},
year = {2007}
}
Comments
4 pages, 4 .eps figures; accepted for publication in Phys. Rev. Lett