IRG-2 has synthesized and characterized a novel, cobalt-based metal-organic framework (MOF) which is a promising candidate for realizing a Kitaev spin liquid.
The material has high-spin d7 Co2+ ions arranged in a honeycomb lattice, each with pseudospin-1/2 ground-state doublets that act as Kitaev spins. Benzoquinone-based linkers mediate interactions between these spins in away that produces frustration. We show that choosing different chemical composition of the linkers allows one to alter the strength of the coupling.
Magnetization data shows antiferromagnetic interactions, but measurements of magnetic susceptibility and specific heat show no spin ordering down to 55 mK.
Thus, the team has demonstrated a novel, promising, and tunable platform for realizing spin liquid physics.
