High Frequency EPR studies of an antiferromagnetic supramolecular grid

The magnetic anisotropy of an antiferromagnetic Mn(II)-[3 x 3] grid was studied by High Frequency Electron Paramagnetic Resonance(HFEPR). The ground state level crossing was observed from various temperature dependent studies. Frequency dependent studies illustrate a breaking of the $\Delta $S~=~0 EPR selection rule due to the strong mixing induced by the comparable exchange and magneto-anisotropy energy scales within the grid. In addition, the field-orientation dependence of the energy gap between the ground and first excited state was studied. All of these studies have contributed to a better understanding of this supramolecular grid, which represents a promising candidate to observe the long sought after quantum tunneling of the N\'{e}el vector.