Spin Chirality in a Molecular Dysprosium Triangle: The Archetype of the Noncollinear Ising Model

Single crystal magnetic studies combined with a theoretical analysis show that cancellation of the magnetic moments in the trinuclear ${\mathrm{Dy}}^{3+}$ cluster $[{\mathrm{Dy}}_3({\mu }_3\mathrm{\text{−}}\mathrm{OH}{)}_2{\mathrm{L}}_3\mathrm{Cl}({\mathrm{H}}_2\mathrm{O}{)}_5]{\mathrm{Cl}}_3$, resulting in a nonmagnetic ground doublet, originates from the noncollinearity of the single-ion easy axes of magnetization of the ${\mathrm{Dy}}^{3+}$ 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.