IO3–-Mediated Short-Range Magnetic Order in 2D Honeycomb LiFe(IO3)2F2

Low-dimensional quantum magnets exhibit exotic quantum phenomena such as short-range order, spin gap, and spin liquid, with potential applications in spintronics and quantum technologies. These quantum phenomena are usually observed in magnetic systems with strong spin exchange mediated by monatomic ions like O 2– , particularly with small quantum spins S . Herein, we report that IO 3 – polyatomic ions mediate efficient spin exchange, resulting in the rarely observed short-range magnetic order at 13.8 K in a novel two-dimensional S = 5/2 iodate-fluoride, LiFe(IO 3 ) 2 F 2 , with a honeycomb lattice. This is also supported by a negative Weiss temperature of −25 K and DFT calculations. The compound further undergoes a three-dimensional antiferromagnetic (AFM) long-range order at 9.9 K following the short-range ordering. In addition, the magnetization measured at 2 K reveals a spin-flop transition around 4.4 T. These findings demonstrate that the IO 3 – bridge provides a new strategy to chemically construct novel low-dimensional magnetic systems, offering a platform to explore exotic quantum phenomena and enabling potential applications in quantum computing and spin-based technologies.