Study of Integer Spin S = 1 in the Polar Magnet β-Ni(IO(3))(2)

Polar magnetic materials exhibiting appreciable asymmetric exchange interactions can potentially host new topological states of matter such as vortex-like spin textures; however, realizations have been mostly limited to half-integer spins due to rare numbers of integer spin systems with broken spatial inversion lattice symmetries. Here, we studied the structure and magnetic properties of the S = 1 integer spin polar magnet β-Ni(IO(3))(2) (Ni(2+), d(8), (3)F). We synthesized single crystals and bulk polycrystalline samples of β-Ni(IO(3))(2) by combining low-temperature chemistry techniques and thermal analysis and characterized its crystal structure and physical properties. Single crystal X-ray and powder X-ray diffraction measurements demonstrated that β-Ni(IO(3))(2) crystallizes in the noncentrosymmetric polar monoclinic structure with space group P2(1). The combination of the macroscopic electric polarization driven by the coalignment of the (IO(3))(−) trigonal pyramids along the b axis and the S = 1 state of the Ni(2+) cation was chosen to investigate integer spin and lattice dynamics in magnetism. The effective magnetic moment of Ni(2+) was extracted from magnetization measurements to be 3.2(1) µ(B), confirming the S = 1 integer spin state of Ni(2+) with some orbital contribution. β-Ni(IO(3))(2) undergoes a magnetic ordering at T = 3 K at a low magnetic field, μ(0)H = 0.1 T; the phase transition, nevertheless, is suppressed at a higher field, μ(0)H = 3 T. An anomaly resembling a phase transition is observed at T ≈ 2.7 K in the C(p)/T vs. T plot, which is the approximate temperature of the magnetic phase transition of the material, indicating that the transition is magnetically driven. This work offers a useful route for exploring integer spin noncentrosymmetric materials, broadening the phase space of polar magnet candidates, which can harbor new topological spin physics.