Investigating the Magnetism of the Honeycomb Arsenate KCo₂(AsO₄)(HAsO₄)

Materials with triangular and honeycomb lattices are of interest as potential quantum materials due to the possibility of magnetic geometric frustration. Combining the triangular lattice of known structure types with ions with desirable electronic and magnetic configurations could induce exotic ground states, such as a quantum spin liquid. We have identified the distorted honeycomb compound KCo₂(AsO₄)(HAsO₄) as a potential quantum spin liquid candidate. In this talk I will discuss our ongoing investigations into characterizing the properties of KCo₂(AsO₄)(HAsO₄), including the hydrothermal synthesis of polycrystalline samples, X-ray diffraction measurements, magnetic susceptibility measurements, neutron diffraction measurements, and DFT calculations. Magnetic susceptibility measurements suggest a transition to a magnetically ordered state below 16 K. The ferromagnetic-like character in the magnetic susceptibility below the transition suggests that the material is not a simple antiferromagnet. DFT calculations suggest a zig-zag antiferromagnetic order within the [ab] -plane. Neutron diffraction measurements at POWGEN reveal a magnetic ordering below ~20 K, and refinement of the magnetic structure is ongoing.