A Mn30 molecular cluster is established to be the largest single-molecule magnet (SMM) discovered to date. Magnetization versus field measurements show coercive fields of about 0.5 T at low temperatures. Magnetization decay experiments reveal an Arrhenius behavior and temperature-independent relaxation below 0.2 K diagnostic of quantum tunneling of magnetization through the anisotropy barrier.The quantum hole digging method is used to establish resonant quantum tunneling. These results demonstrate that large molecular nanomagnets,having a volume of 15 nm^3, with dimensions approaching the mesoscale can still exhibit the quantum physics of the microscale.
@article{arxiv.cond-mat/0306303,
title = {Quantum Tunneling of Magnetization in a Large Molecular Nanomagnet -- Approaching the Mesoscale},
author = {W. Wernsdorfer and M. Soler and D. N. Hendrickson and G. Christou},
journal= {arXiv preprint arXiv:cond-mat/0306303},
year = {2007}
}