Spin Chirality in a Molecular Dysprosium Triangle : The archetype of the non-collinear Ising Model
Résumé
Single crystal magnetic studies combined with a theoretical analysis show that cancellation of the magnetic moments in the trinuclear Dy3 cluster Dy33-OH2L3ClH2O5Cl3, resulting in a nonmagnetic ground doublet, originates from the noncollinearity of the single-ion easy axes of magnetization of the Dy3 ions that lie in the plane of the triangle at 120 one from each other. This gives rise to a peculiar chiral nature of the ground nonmagnetic doublet and to slow relaxation of the magnetization with abrupt accelerations at the crossings of the discrete energy levels.