Alternating single-ion anisotropy and weak ferromagnetism in a spin-1 antiferromagnet

Molecular building blocks provide unique structural degrees of freedom and enable the creation of quantum magnets that are hard to realise in entirely inorganic materials. We propose to measure the low-temperature magnetic structure of a material in which S = 1 ions are linked by non-linear molecular bridges. Symmetry analysis raises the intriguing possibility of a ground-state canted phase in which the observed weak ferromagnetism arises not from the Dzyaloshinskii-Moriya interaction, as occurs in the vast majority of cases, but instead from a novel, alternating single-ion anisotropy caused by the crystal structure of interlocking chiral chains. Observation of this state would highlight a new type of coupling between external magnetic field and a quantum antiferromagnetic ground state and further demonstrate that molecule-based magnets can support unique structure-property connections.