Neutron spectroscopy and magnetic relaxation of the Mn$_6$ nanomagnets
  Inelastic neutron scattering has been used to determine the microscopic Hamiltonian describing two high-spin variants of the high-anisotropy Mn$_6$ nanomagnet. The energy spectrum of both systems is characterized by the presence of several excited total-spin multiplets partially overlapping the S=12 ground multiplet. This implies that the relaxation processes of these molecules are different from those occurring in prototype giant-spin nanomagnets. In particular, we show that both the height of the energy barrier and resonant tunnelling processes are greatly influenced by low-lying excited total-spin multiplets. 
S. Carretta, T. Guidi, P. Santini, G. Amoretti, O. Pieper, B. Lake, J.   van Slageren, F. El Hallak, W. Wernsdorfer, H. Mutk...