Magnetic properties of a Heisenberg coupled-trimer molecular magnet: General results and application to spin- 1 2 vanadium clusters

We report predictions for the energy eigenstates and inelastic neutron-scattering excitations of an isotropic Heisenberg hexamer consisting of general spin S and S′ trimers. Specializing to spin-1/2 ions, we give analytic results for the energy excitations, magnetic susceptibility, and inelastic neutron-scattering intensities for this hexamer system. To examine this model further, we compare these calculations to the measured magnetic susceptibility of a vanadium material, which is considered to be well-defined magnetically as an isolated S=1/2V4+ trimer model. Using our model, we determine the amount of intertrimer coupling that can be accommodated by the measured susceptibility and predict the inelastic neutron-scattering spectrum for comparison with future measurements.