Frustrated magnetism of the spin-1 kagome antiferromagnet-BaNi(VO)(OH).

We propose the newly synthesized-BaNi(VO)(OH)(space group:R3‾m) as a candidate for the spin-1 kagome Heisenberg antiferromagnet (KHA). The compound features a uniform kagome lattice of Ni(= 1) ions with a large interlayer distance. High-field measurements at low temperatures reveal a susceptibility local minimum at ∼9 T, resembling a 1/3 magnetization plateau as predicted by the pure= 1 KHA model. Below ∼6 K, approximately 1% of the spins exhibit spin-glass order, which may be attributed to the nanocrystalline grain size of ∼50 nm. Despite the antiferromagnetic exchange coupling strength of ∼7 K, the majority of spins remain disordered down to ∼0.1 K as indicated by the observed power-law behaviors in magnetic specific heatCm∝T1.4. Our results demonstrate that the low-energy magnetic excitations in-BaNi(VO)(OH)are gapless, which contradicts the current theoretical expectations of the ideal model.