Ferromagnetic-like behavior emerging from local CoO 6 honeycomb motifs in Co-doped NaSbO 3 thin films

The strongly correlated oxides with a honeycomb lattice have attracted vast attention due to their interesting magnetic behaviors and emergent quantum effects such as Majorana fermions generated from Kitaev spin liquid. High-quality single crystal samples with delicately controlled composition and strain are highly required in this area. In this work, honeycomb structure built by edge-sharing CoO₆ octahedra is stabilized in ilmenite matrix by doping 4% Co into NaSbO₃. By performing magnetic measurements and first principles calculations, it is suggested that honeycomb local motifs containing Co^2+ (3d^7) cobalt may exist in Co-doped NaSbO₃ thin films, and exhibit ferromagnetic-like transition at 88 K. Meanwhile, the interlayer dipolar interaction may lead to antiferromagnetic coupling between the nearest layers. This work reveals the possibility to embed 3d^7 honeycomb structure into an ilmenite matrix and provides a platform for future spin liquid exploration as well as quantum information technology.