Pursuit of quantum spin liquid (QSL) states in the two-dimensional (2D) honeycomb lattice is particularly appealing and challenging. Here, we report the hereovalent substitution strategy to tune the crystal structure and magnetism of the honeycomb-derived oxide family ANi 2 TeO 6 . Substituting A 2+ with the charge-balanced chemical unit 0.5Na + + 0.5 RE 3+ yields a new family of oxides Na 0.5 RE 0.5 Ni 2 TeO 6 (N RE NTO, RE = La–Lu and Y), where the size mismatch between Na + and RE 3+ drives an orthorhombic-to-hexagonal reconstructive structural transition. These two structures differ remarkably in connectivity geometry among Ni 2 TeO 6 2– double-rutile chains, resulting in different hexagonal channels topologies stuffed by Na + / RE 3+ cations. Nevertheless, both structures retain a similar buckled Ni 2+ honeycomb lattice, the different degrees of distortion, however, give rise to distinct magnetic ground states. Specifically, the orthorhombic NLaNTO shows long-range canted antiferromagnetic ordering below 26 K, whereas the hexagonal NLuNTO exhibits typical low-dimensional and strongly frustrated magnetic behavior with no signature of long-range magnetic ordering down to 10 K. These results demonstrate that subtle structural changes significantly modify magnetic exchange pathways in this honeycomb-derived framework. Na 0.5 RE 0.5 Ni 2 TeO 6 provides a chemically tunable platform that couples composition, lattice distortion, and magnetic dimensionality, offering a route to approaching novel magnetic ground states, including QSL-like behavior.
Ma et al. (Wed,) studied this question.